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NYSTCE Earth Science (162) study materials
NYSTCE Earth Science (162) study resources

NYSTCE Earth Science (162) practice questions

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Question 1Foundations of scientific inquiry

A student measures the mass of a mineral sample three times and obtains 12.4 g, 12.5 g, and 12.4 g. The accepted value for the sample is 13.0 g. Which statement best describes these measurements?

  1. They are neither accurate nor precise.
  2. They are both accurate and precise.
  3. They are precise but not accurate. Correct answer.
  4. They are accurate but not precise.

Explanation

Precision refers to how closely repeated measurements agree with one another, while accuracy refers to how close a measurement is to the accepted value. The three trials cluster tightly together (high precision) but all fall about 0.6 g below the accepted value (low accuracy).

Question 2Foundations of scientific inquiry

In an experiment testing how temperature affects the dissolving rate of a salt, which variable must be deliberately changed by the investigator?

  1. The dependent variable
  2. The control variable
  3. The independent variable Correct answer.
  4. The constant variable

Explanation

The independent variable is the factor the experimenter manipulates, here the temperature of the water. The dependent variable is the measured outcome (dissolving rate), while controlled variables are held constant to keep the test fair.

Question 3Foundations of scientific inquiry

A geologist reports that a rock layer is 250 million years old. Which type of investigation does this statement most directly represent?

  1. A theoretical prediction with no data
  2. An empirical measurement of the rock's age Correct answer.
  3. A pseudoscientific claim that cannot be tested
  4. A hypothesis awaiting any observation

Explanation

Radiometric dating produces quantitative age estimates grounded in measured isotope ratios, making this an empirical claim supported by observation and measurement. Empirical investigations rely on data gathered from the natural world rather than speculation.

Question 4Foundations of scientific inquiry

Which SI unit is appropriate for reporting the density of a rock sample in Earth science laboratory work?

  1. Meters per second
  2. Newtons per meter
  3. Grams per cubic centimeter Correct answer.
  4. Joules per kilogram

Explanation

Density is mass per unit volume, and in laboratory Earth science it is commonly expressed as grams per cubic centimeter (g/cm³). The other choices correspond to surface tension or spring constant, specific energy, and speed, respectively.

Question 5Foundations of scientific inquiry

A student wants to determine whether a new soil additive increases plant growth. Which procedure best reflects a controlled experimental design?

  1. Observe plants grown with the additive in several different gardens.
  2. Grow two identical groups of plants, adding the additive to one group only. Correct answer.
  3. Add the additive to every plant and record the tallest height reached.
  4. Ask classmates whether they believe the additive helps plants grow.

Explanation

A controlled experiment compares a treatment group with a control group that differs only in the variable being tested. Keeping all other conditions identical isolates the effect of the additive on growth.

Question 6Foundations of scientific inquiry

Which statement best distinguishes a scientific hypothesis from a scientific theory?

  1. A hypothesis is always correct, while a theory is always being revised.
  2. A hypothesis is a testable tentative explanation, while a theory is a well-supported explanatory framework. Correct answer.
  3. A hypothesis is a proven fact, while a theory is an untested guess.
  4. A hypothesis applies only to physics, while a theory applies only to Earth science.

Explanation

In science, a hypothesis is a proposed, testable explanation for a specific observation, whereas a theory is a broad explanation supported by extensive evidence. A theory is not a mere guess; it is among the most robust products of scientific inquiry.

Question 7Foundations of scientific inquiry

A scientist repeats a measurement of a mineral's hardness five times and obtains nearly identical results each time. This outcome most directly demonstrates which quality of the data?

  1. Bias
  2. Reliability Correct answer.
  3. Accuracy
  4. Validity

Explanation

Reliability describes the consistency of repeated measurements, which is exactly what identical repeated results demonstrate. Reliability says nothing by itself about whether the values match the true hardness.

Question 8Foundations of scientific inquiry

Which practice is most important for ensuring that an Earth science investigation's results can be reproduced by other researchers?

  1. Rounding all measurements to whole numbers
  2. Recording detailed procedures and data for publication Correct answer.
  3. Reporting only the results that support the hypothesis
  4. Relying on a single trial for each condition

Explanation

Reproducibility requires that others can follow the methods and analyze the data, so complete documentation of procedures and observations is essential. Selective reporting and single trials undermine the credibility and repeatability of results.

Question 9Foundations of scientific inquiry

A student uses a graduated cylinder to find the volume of an irregular rock by displacement. The water level rises from 40 mL to 55 mL. What is the rock's volume?

  1. 95 mL
  2. 40 mL
  3. 55 mL
  4. 15 mL Correct answer.

Explanation

Water displacement measures the volume of the rock as the difference between the final and initial water levels. Subtracting 40 mL from 55 mL gives 15 mL, which equals the volume of the submerged rock.

Question 10Foundations of scientific inquiry

A geologist measures a fossil's age at 66 million years with an uncertainty of ±2 million years. Which statement correctly interprets this result?

  1. The measurement is invalid because it has uncertainty.
  2. The true age is exactly 66 million years.
  3. The true age is likely between 64 and 68 million years. Correct answer.
  4. The fossil could be anywhere from 0 to 66 million years old.

Explanation

An uncertainty of ±2 million years means the reported value spans a range from 2 million years below to 2 million years above the estimate. This range represents the measurement's confidence interval, not an exact value.

Question 11Foundations of scientific inquiry

A researcher plots earthquake epicenter data and notices that most epicenters align along a narrow belt. Which reasoning step best moves this observation toward an explanation?

  1. Assuming the belt exists without further investigation
  2. Discarding epicenters that fall outside the belt
  3. Proposing that the belt marks a plate boundary and testing predictions from that idea Correct answer.
  4. Concluding immediately that the alignment is coincidental

Explanation

Turning a pattern into an explanation requires formulating a testable hypothesis and evaluating predictions against evidence. The plate-boundary hypothesis predicts additional phenomena, such as volcanic activity, that can be checked.

Question 12Foundations of scientific inquiry

Two students measure the same mineral sample's mass. Student A reports 24.6 g and Student B reports 24.7 g. Which statement about the measurements is most defensible?

  1. The mineral's mass cannot be determined.
  2. The measurements are consistent within measurement uncertainty. Correct answer.
  3. Student B must have made an error.
  4. The two measurements are unrelated.

Explanation

A difference of 0.1 g is well within the uncertainty typical of common laboratory balances, so the measurements agree. Small variations between observers are expected and do not indicate error.

Question 13Foundations of scientific inquiry

A student hypothesizes that warmer water dissolves salt faster. Which observation would best support this hypothesis?

  1. Salt dissolves more slowly in heated water than in cold water.
  2. Salt dissolves more quickly in heated water than in room-temperature water. Correct answer.
  3. Salt dissolves at the same rate in all water temperatures.
  4. Salt does not dissolve in water at any temperature.

Explanation

A hypothesis is supported when observations match its prediction. The prediction here is that warmer water increases dissolving rate, so faster dissolving in heated water supports it.

Question 14Foundations of scientific inquiry

A team maps a fault and measures offset rock layers on either side. Which type of data are they primarily collecting?

  1. Anecdotal observations
  2. Quantitative field data Correct answer.
  3. Unverifiable opinions
  4. Historical narratives

Explanation

Measuring offset distances and mapping fault geometry produce numerical and spatial data that can be analyzed statistically. Such measurements are the hallmark of quantitative field investigation.

Question 15Foundations of scientific inquiry

A scientist studying a volcanic region uses satellite imagery to detect ground deformation over time. Which statement best describes the role of this technology in the investigation?

  1. It eliminates all uncertainty from the study.
  2. It replaces the need for any ground-based measurements.
  3. It proves the volcano will erupt on a specific date.
  4. It provides remote-sensing data that can be compared across time to detect change. Correct answer.

Explanation

Remote sensing supplies repeated, comparable observations of surface change, which support inferences about magmatic activity. It complements rather than replaces field data and cannot predict exact eruption dates.

Question 16Foundations of scientific inquiry

A lab group needs to report the density of a rock to the correct number of significant figures. The mass is 45.2 g and the volume is 15.0 cm³. What is the density expressed to the correct precision?

  1. 3.0 g/cm³
  2. 3.01 g/cm³ Correct answer.
  3. 3 g/cm³
  4. 3.013 g/cm³

Explanation

Dividing 45.2 g by 15.0 cm³ gives about 3.013 g/cm³. Both inputs have three significant figures, so the quotient should be rounded to three significant figures, giving 3.01 g/cm³.

Question 17Foundations of scientific inquiry

A student claims that a rock is sedimentary because it contains layers. Which response best reflects scientific skepticism?

  1. Accept the claim because layered rocks are common.
  2. Reject the claim because layering is never reliable.
  3. Ask what evidence would distinguish sedimentary layering from other layered formations. Correct answer.
  4. Ignore the claim because it cannot be tested.

Explanation

Scientific skepticism involves demanding evidence and considering alternative explanations. Layering can also occur in igneous and metamorphic rocks, so asking what evidence would discriminate among possibilities is the appropriate critical response.

Question 18Foundations of scientific inquiry

Which change to an investigation would most improve the reliability of its conclusions?

  1. Conducting the experiment only once to save time
  2. Selecting data that agree with the hypothesis
  3. Changing several variables between trials
  4. Increasing the number of trials and averaging the results Correct answer.

Explanation

More trials reduce the influence of random error and yield more stable averages, improving reliability. Selective data use and uncontrolled variables instead introduce bias and confounding.

Question 19Foundations of scientific inquiry

A student graphs temperature versus depth in a borehole and finds a linear trend. Which statement about the trend is most scientifically appropriate?

  1. The trend is meaningless because it is only a graph.
  2. The linear trend suggests a consistent rate of temperature increase with depth. Correct answer.
  3. The trend proves the exact temperature at every depth.
  4. The trend should be ignored unless it is perfectly linear.

Explanation

A linear relationship on a graph indicates a constant rate of change, here a steady geothermal gradient. Graphs summarize patterns in data, and the slope quantifies the rate.

Question 20Foundations of scientific inquiry

A researcher finds that a new instrument gives readings consistently 0.5 g higher than a calibrated balance. This discrepancy is best described as which type of error?

  1. Systematic error Correct answer.
  2. Random error
  3. Human error
  4. Sampling error

Explanation

A consistent offset in one direction across all readings is the signature of systematic error, often caused by improper calibration. Random error, by contrast, scatters in both directions.

Question 21Foundations of scientific inquiry

An Earth science class is designing an investigation of stream erosion. Which question is best formulated as a testable scientific question?

  1. Why is water wet?
  2. Is erosion good or bad?
  3. What is the most beautiful stream in the region?
  4. How does stream gradient affect the size of sediment transported? Correct answer.

Explanation

A testable question specifies measurable variables whose relationship can be examined through observation or experiment. Stream gradient and sediment size are both quantifiable and can be compared systematically.

Question 22Foundations of scientific inquiry

A study reports a correlation between sunspot activity and regional rainfall but no mechanism. Which conclusion is most scientifically sound?

  1. The correlation must be a coincidence and should be discarded.
  2. The correlation proves sunspots cause the rainfall pattern.
  3. Correlation alone does not establish causation; a mechanism must be tested. Correct answer.
  4. The study should be accepted because the data are numerical.

Explanation

Correlation indicates that two variables vary together but does not by itself demonstrate a causal link. Establishing causation requires a plausible mechanism and controlled testing that rules out confounding factors.

Question 23Foundations of scientific inquiry

A student's model predicts that a coastal region will experience increased erosion as sea level rises. Which action would best test the model's validity?

  1. Assuming the model is correct because it is quantitative
  2. Comparing predicted erosion rates with measured shoreline change over several decades Correct answer.
  3. Presenting the model to classmates for a vote
  4. Adding more assumptions without collecting data

Explanation

Models are validated by comparing their predictions with independent observations from the real world. Long-term shoreline measurements provide the empirical test of the erosion prediction.

Question 24Foundations of scientific inquiry

A geologist uses multiple independent methods (radiometric dating, fossil correlation, and magnetic stratigraphy) to date a rock sequence. Why does agreement among methods strengthen the conclusion?

  1. Independent methods always produce identical results.
  2. Independent lines of evidence converging on the same result reduce the likelihood of error. Correct answer.
  3. Agreement guarantees the result is absolutely certain.
  4. Multiple methods eliminate the need for uncertainty estimates.

Explanation

Convergent evidence from methods with different assumptions and error sources makes a shared systematic error less likely. This convergence increases confidence in the conclusion without producing absolute certainty.

Question 25Foundations of scientific inquiry

An investigator finds that a data set contains one value far outside the range of all other measurements. Which approach best reflects sound scientific practice?

  1. Keep the outlier and ignore it in all calculations.
  2. Change the outlier to match the other values.
  3. Delete the outlier immediately because it is inconvenient.
  4. Investigate the outlier for possible instrument or procedural causes before deciding to exclude it. Correct answer.

Explanation

Outliers may reflect genuine phenomena or measurement problems, so they should be examined before any decision about inclusion. Arbitrarily removing or altering data is a form of scientific misconduct.

Question 26Foundations of scientific inquiry

In an Earth science investigation, which component of the experimental design serves as the standard of comparison against which the effect of the manipulated variable is judged?

  1. The control group Correct answer.
  2. The sample size
  3. The dependent variable
  4. The hypothesis statement

Explanation

A control group is held at standard or untreated conditions so that any difference observed in the experimental group can be attributed to the manipulated variable rather than to other factors. It provides the baseline for comparison in a controlled investigation.

Question 27Foundations of scientific inquiry

A seismograph records ground motion continuously and produces a printed trace. In the language of scientific inquiry, the printed trace is best described as which of the following?

  1. An inference drawn from the data
  2. A theory of seismic wave propagation
  3. A raw data record produced by an instrument Correct answer.
  4. A hypothesis about earthquake timing

Explanation

An instrument such as a seismograph generates direct observations, which constitute raw data. Inference, hypothesis, and theory are interpretive products built on such records rather than the records themselves.

Question 28Foundations of scientific inquiry

Which unit is an SI base unit that Earth scientists routinely use when reporting the mass of a mineral specimen?

  1. Joule
  2. Kilogram Correct answer.
  3. Pascal
  4. Newton

Explanation

The kilogram is the SI base unit of mass. The newton is a derived unit of force, the joule of energy, and the pascal of pressure, so none of those reports mass directly.

Question 29Foundations of scientific inquiry

A field geologist records that an outcrop is located 3.2 km northeast of a named benchmark. This record is best classified as which kind of observation?

  1. Theoretical and predictive
  2. Quantitative and spatial Correct answer.
  3. Qualitative and descriptive
  4. Experimental and manipulative

Explanation

The record includes both a measured numerical distance and a directional position, making it quantitative and spatial. Descriptive qualitative observations lack measured values, and no prediction or manipulation occurred.

Question 30Foundations of scientific inquiry

Which statement correctly describes the role of peer review in the publication of an Earth science study?

  1. It guarantees that the study's conclusions are true.
  2. It subjects the methods and reasoning to independent expert scrutiny before publication. Correct answer.
  3. It replaces the need for the study to be replicated.
  4. It confirms that the field data were collected by the reviewers themselves.

Explanation

Peer review is independent evaluation of a manuscript's methods, evidence, and reasoning by qualified experts before publication. It improves quality but does not guarantee truth or substitute for replication by others.

Question 31Foundations of scientific inquiry

A student wants to test whether the grain size of sediment affects how steeply a stream deposit slopes. Which variable should the student deliberately change during the trials?

  1. The grain size of the sediment Correct answer.
  2. The volume of water delivered
  3. The slope angle of the flume
  4. The temperature of the room

Explanation

The manipulated (independent) variable is the one the investigator deliberately varies, which here is grain size. The slope that develops is the responding variable, while water volume and room temperature should be held constant.

Question 32Foundations of scientific inquiry

Which of the following is the best example of a qualitative observation made during an Earth science field study?

  1. The sample fizzes when dilute acid is applied. Correct answer.
  2. The water temperature is 12 degrees Celsius.
  3. The sample mass is 38.1 g.
  4. The layer is 2.4 m thick.

Explanation

A qualitative observation describes a property or behavior without assigning a measured numerical value, as in noting an effervescent reaction. The other choices all report measurements.

Question 33Foundations of scientific inquiry

An Earth science class must select equipment to measure the pH of rainwater samples in the field. Which instrument is designed specifically for that measurement?

  1. A spring scale
  2. A graduated cylinder
  3. A hand lens
  4. A pH meter with a calibrated electrode Correct answer.

Explanation

A pH meter with a calibrated electrode is designed to measure hydrogen ion activity and report pH directly. The other instruments measure magnification, force or weight, and volume, respectively.

Question 34Foundations of scientific inquiry

A student records the depth of a lake at ten stations and reports the mean depth as 14.3 m. Another student reports the same data as 14 m. Which statement best explains why the two reports differ?

  1. The second student used a different unit system.
  2. The reports differ in the number of significant figures retained. Correct answer.
  3. The mean depth cannot be calculated from ten stations.
  4. One student measured incorrectly, so one value must be wrong.

Explanation

Both reports can be consistent with the same data set; they differ in how many significant figures were kept. Rounding to the nearest meter reduces precision but does not necessarily indicate error.

Question 35Foundations of scientific inquiry

A hydrologist wants to determine whether fertilizer runoff raises nitrate levels in a stream. Which design would best allow a causal conclusion?

  1. Measure nitrate upstream and downstream of a runoff outfall before and after fertilizer application. Correct answer.
  2. Measure nitrate only at the stream's mouth during a single afternoon.
  3. Survey residents about whether they believe the stream is polluted.
  4. Sample nitrate at many streams once and compare with nearby farm density.

Explanation

A before-and-after comparison at upstream and downstream sites controls for location and timing, isolating the effect of the runoff input. Single-time or opinion-based approaches cannot separate the runoff effect from confounding factors.

Question 36Foundations of scientific inquiry

A researcher measures the density of five identical basalt cubes and obtains 2.96, 2.98, 2.97, 2.99, and 2.97 g/cm³. Which conclusion about the measurements is best supported?

  1. The measurements are accurate but imprecise.
  2. The measurements cannot be averaged meaningfully.
  3. The measurements are precise but may still be inaccurate. Correct answer.
  4. The measurements show a strong systematic error.

Explanation

The values cluster tightly, indicating high precision, but precision alone does not establish accuracy relative to a known value. Without comparison to an accepted density, accuracy cannot be confirmed.

Question 37Foundations of scientific inquiry

A geologist uses a map with a scale of 1:24,000. Two outcrops are 5.0 cm apart on the map. What is the actual ground distance between them?

  1. 120 m
  2. 24,000 m
  3. 1,200 m Correct answer.
  4. 12,000 m

Explanation

A scale of 1:24,000 means 1 cm on the map represents 24,000 cm on the ground. Multiplying 5.0 cm by 24,000 cm gives 120,000 cm, which equals 1,200 m.

Question 38Foundations of scientific inquiry

A student's data table lists a rock's volume as 12.5 mL and its mass as 33.8 g. Which density value is correctly rounded to the appropriate number of significant figures?

  1. 2.70 g/mL Correct answer.
  2. 2.704 g/mL
  3. 3 g/mL
  4. 2.7 g/mL

Explanation

Dividing 33.8 g by 12.5 mL gives about 2.704 g/mL, and the result should be reported to three significant figures, matching the least precise input. Thus 2.70 g/mL is appropriate.

Question 39Foundations of scientific inquiry

A research team wants to reduce sampling bias when selecting sites to measure soil erosion on a hillside. Which sampling approach best addresses this concern?

  1. Sampling only where erosion is visibly severe
  2. Sampling only near the trailhead
  3. Randomly selecting sites across the entire hillside Correct answer.
  4. Choosing sites that are easiest to reach

Explanation

Random selection across the full area gives every location an equal chance of inclusion, reducing bias from accessibility or appearance. Convenience or appearance-based selection systematically over- or under-represents conditions.

Question 40Foundations of scientific inquiry

A scientist builds a computer model that simulates groundwater flow. Which practice most strengthens confidence in the model's predictions?

  1. Increasing the visual detail of the model's output graphics
  2. Testing the model against measured field data from a known aquifer Correct answer.
  3. Publishing the model before validation
  4. Using the most recently released software version

Explanation

A model gains credibility when its predictions agree with independent field observations. Visual detail, software recency, or early publication do not establish that the model represents reality.

Question 41Foundations of scientific inquiry

A student predicts that a sample of limestone will react with dilute hydrochloric acid. The student places a drop of acid on the sample and observes bubbling. In the context of this investigation, the bubbling is best described as which of the following?

  1. The prediction
  2. The conclusion of a controlled experiment
  3. The observation that supports the prediction Correct answer.
  4. The hypothesis

Explanation

The bubbling is a direct observation recorded during the test. The hypothesis was the proposed expectation, the prediction was the stated outcome, and a conclusion would be the interpretation drawn after comparing observation with prediction.

Question 42Foundations of scientific inquiry

An Earth science student uses a bar graph to display the number of earthquakes in each of five magnitude categories. Which feature of the graph most directly communicates the frequency of events in each category?

  1. The title of the graph
  2. The order of the categories
  3. The height of each bar Correct answer.
  4. The color of each bar

Explanation

In a bar graph of counts, bar height encodes the frequency for each category. Color, order, and title aid interpretation but do not represent the numerical counts.

Question 43Foundations of scientific inquiry

A geologist measures the strike and dip of a rock layer at several nearby outcrops and finds consistent values. What does this consistency most directly indicate?

  1. The layer's orientation is consistent across the sampled area. Correct answer.
  2. The layer has been folded into a tight syncline.
  3. The rock must be igneous.
  4. The measurements are unreliable.

Explanation

Repeated, consistent strike and dip readings indicate that the layer maintains a similar orientation over the sampled area. Consistency supports reliability rather than undermining it, and it does not by itself determine rock type or fold geometry.

Question 44Foundations of scientific inquiry

A student's investigation of soil permeability yields results that contradict the accepted value. Which response best reflects sound scientific practice?

  1. Adjust the results to match the accepted value.
  2. Conclude that the accepted value is definitely wrong.
  3. Discard the data because the accepted value must be right.
  4. Repeat the procedure, check for procedural errors, and report the findings. Correct answer.

Explanation

Unexpected results should prompt careful rechecking and replication before any interpretation is accepted. Adjusting data is misconduct, and neither dismissing the data nor overturning established values on one trial is justified.

Question 45Foundations of scientific inquiry

A researcher uses a geographic information system to overlay a slope map, a rock-type map, and a landslide inventory. Which advantage of this approach is most relevant to the investigation?

  1. It allows spatial relationships among multiple variables to be examined together. Correct answer.
  2. It eliminates the need for field verification.
  3. It replaces statistical analysis of the data.
  4. It guarantees that landslide causes are identified.

Explanation

Overlaying layers in a GIS allows the investigator to examine how landslide locations relate to slope and rock type simultaneously. It supports analysis but does not replace field checks, causal inference, or statistics.

Question 46Foundations of scientific inquiry

A team uses a remote-sensing instrument that measures reflected infrared radiation to estimate surface mineral composition. Which limitation most directly affects the interpretation of such data?

  1. Reflected radiation carries no information about surface materials.
  2. Remote sensing cannot cover large areas.
  3. Surface cover such as vegetation or dust can obscure the underlying mineral signature. Correct answer.
  4. Infrared sensors cannot record data at night.

Explanation

Reflectance spectra record what is exposed at the surface, so vegetation, dust, or weathering rinds can mask the bedrock signature. This is a key interpretive limitation of spectral remote sensing.

Question 47Foundations of scientific inquiry

A researcher reports that a new method of dating a sediment layer yields ages with a stated uncertainty of plus or minus 0.5 million years, while an established method yields plus or minus 3 million years. Which interpretation is best supported?

  1. The new method is necessarily more accurate than the established method.
  2. The new method is more precise, but its accuracy requires independent verification. Correct answer.
  3. The established method must be invalid.
  4. Uncertainty values indicate systematic error only.

Explanation

A smaller stated uncertainty indicates greater precision, not necessarily greater accuracy. Accuracy requires comparison with independent evidence, so the new method's closeness to true age must still be verified.

Question 48Foundations of scientific inquiry

A study finds a strong statistical correlation between years of high volcanic activity and years of cooler global average temperature. Which additional step is most important before concluding that volcanism caused the cooling?

  1. Reporting the correlation in a press release
  2. Identifying and testing a physical mechanism linking volcanic aerosols to cooling Correct answer.
  3. Confirming that the correlation coefficient is high
  4. Collecting more years of the same two variables

Explanation

Correlation alone cannot establish causation; a plausible physical mechanism must be identified and tested against independent evidence. Additional years of the same two variables or a high coefficient do not resolve the causal question.

Question 49Foundations of scientific inquiry

A geologist combines radiometric ages, fossil assemblages, and magnetic reversals to establish a timeline for a rock sequence. Which principle does this approach best illustrate?

  1. Magnetic data are unreliable for dating.
  2. Converging independent lines of evidence strengthen a conclusion. Correct answer.
  3. Fossils cannot be used to correlate rock layers.
  4. Relying on a single line of evidence is sufficient.

Explanation

When independent methods yield consistent results, confidence in the conclusion increases because a single method's error is unlikely to be matched by unrelated methods. This convergence is a hallmark of robust scientific reasoning.

Question 50Foundations of scientific inquiry

A data set of stream discharge contains one value far larger than all the others, and the investigator suspects a transcription error. Which approach best reflects sound data handling?

  1. Keep the value and ignore its effect on the analysis.
  2. Delete the value silently and report the mean of the rest.
  3. Investigate the original record, then report the value and any exclusion with justification. Correct answer.
  4. Replace the value with the mean of the other measurements.

Explanation

Outliers should be investigated against the original records before any decision is made. If excluded, the exclusion and its rationale must be documented so the analysis remains transparent and reproducible.