Charts, Tables, and Data Visualization
This domain tests whether you can choose a visualisation that fits the data, build it from the right range, and use table objects so ranges grow automatically instead of being redefined by hand.
Choosing the chart type
- Column or bar charts compare discrete categories.
- Line charts show a trend across a continuous sequence, typically time.
- Scatter charts plot two numeric variables against their true values to reveal correlation.
- Pie charts show parts of a single whole and become unreadable beyond a handful of slices.
- Histograms show the distribution of one numeric variable; box plots compare distributions across groups.
A crucial distinction: a line chart treats the horizontal axis as evenly spaced categories, while a scatter chart positions points by their actual x values. Unevenly spaced readings therefore produce a misleading line chart and a truthful scatter.
Anatomy of a chart
Every chart reads series values from ranges and category labels from a range or column. Axis titles, data labels, legends, and gridlines are optional elements that can be added or removed without touching the data. A secondary axis is appropriate when two series use different scales, not when one series is simply smaller.
Table objects
Creating a table with Ctrl+T gives it a name and structured references such as Table1[Sales]. The table expands when a row or column is typed beneath or beside it, calculated columns fill down automatically, a total row can be toggled on, and charts or pivot tables built on the table extend with it.
Worked example
Monthly readings taken on days 1, 4, 20, and 28 are charted. A line chart places the four points at equal intervals and implies steady change. The correct choice is a scatter chart with straight lines, because the x-axis then reflects the real gaps between readings.
Traps that cost marks
- Pie charts with a dozen categories, or pie charts of values that do not sum to a meaningful whole.
- Hard-coded ranges that leave new rows out of the chart.
- Charts showing blank series because the source range includes header text counted as a value.