DSST Principles of Statistics case studies
DSST Principles of Statistics · Put your knowledge to work in context.
Principles of Statistics is a DSST (DANTES Subject Standardized Tests) exam that can earn you 3 semester hours of baccalaureate credit at participating colleges and universities. It is aimed at students who already know introductory statistics, either from coursework, self-study, or work experience, and who want credit by examination instead of repeating a course. The DSST Principles of Statistics case studies are 5 cases and about 3,277 words.
1Two plating lines and the shape of defect counts
A metal-finishing plant monitors microscopic pits per 10 cm2 on plated panels from two lines. In the same week, Line A produced n = 120 sampled panels with mean 7.4 pits, median 6.9, SD 2.1, skewness +1.35, and excess kurtosis +3.8.
696 words, about 3 min2After-hours arrivals at a rural urgent-care clinic
A rural urgent-care clinic is modeling after-hours arrivals to decide how many exam rooms to staff. Historical logs show arrivals average 3.5 per hour, with no strong trend across the evening; the clinic treats arrivals as independent and occurring at a constant rate.
652 words, about 3 min3Fertilizer dose and tomato yield: prediction beyond the trial
A greenhouse trial tested six fertilizer doses from 0 to 24 g per tomato plant, with four plots at each dose (n = 24). The fitted least-squares line is yield = 3.1 + 0.42x, where yield is kg per plot and x is grams of fertilizer per plant.
686 words, about 3 min4Readmission rates and a confidence interval that straddles zero
A hospital quality team compares a transitional-care program with usual care for 30-day readmissions. In the program, 64 of 400 patients were readmitted; in usual care, 100 of 500 were readmitted.
595 words, about 3 min5Sodium in muffins: a sample mean and a skewed population
An industrial bakery fills muffin cups by weight, and sodium content per muffin is right-skewed: the population mean is 210 mg and the population standard deviation is 45 mg, with a few very high values from uneven salt blending. A food inspector plans to take a random sample of 49 muffins and will flag the batch if the sample mean sodium exceeds 220 mg.
648 words, about 3 min