Describing Data with Numbers and Graphs — HS Statistics practice questions

24 multiple-choice questions and 41 flashcards on Describing Data with Numbers and Graphs, about 16% of the HS Statistics bank. Every one carries a written rationale.

Written and maintained by the CoStudy team · last updated 2026-10-02 · how we write and review questions

What this chapter covers

Describing Data with Numbers and Graphs is one of 7 chapters in CoStudy's HS Statistics bank, and it holds 24 of the bank's 150 multiple-choice questions — roughly 16% of the total. That proportion is not arbitrary: chapters follow the certifying body's published exam outline, and the number of questions in each is set by that domain's published weight, so the share of your practice time this chapter takes matches the share of the real exam it accounts for.

Studying by chapter is worth doing once you have a diagnostic score. A single overall percentage tells you whether you are close; it does not tell you which domain is dragging. Working a weak chapter in isolation, and re-testing it in isolation, is the fastest way to move a score that has stalled — and it is why the mock exams in CoStudy report by domain rather than as one number.

Free Describing Data with Numbers and Graphs practice questions

3 questions drawn from this chapter, with the full rationale shown — the controlling principle behind the right answer, and why each wrong option tempts and fails.

A distribution is skewed right (a long tail of high values). Typically:

the mean is less than the median
the mean is greater than the median
the mean equals the median
the median is greater than the mean

Answer: B — the mean is greater than the median

B) Correct — The high values pull the mean toward the tail. A) Describes a left-skewed distribution. C) Describes a symmetric distribution. D) Also describes left skew.

A box plot displays:

the mean and standard deviation
every individual value
the counts of each category
the five-number summary

Answer: D — the five-number summary

D) Correct — Minimum, Q1, median, Q3, and maximum (with outliers marked). A) A box plot is built from quartiles, not the mean and SD. B) That is a dot plot or stem plot. C) That is a bar chart.

What is the mean of 4, 6, 8, 10, 12?

40
8
10
6.67

Answer: B — 8

B) Correct — Sum 40 ÷ 5 values = 8. A) Adds the values but forgets to divide by how many there are. C) Divides the sum by 4 instead of 5. D) Divides the sum by 6 instead of 5.

Describing Data with Numbers and Graphs flashcards

4 cards from the 41 in this chapter.

Quartiles?

Q1 (25th), Q2 (50th = median), Q3 (75th).

Standard deviation?

Square root of variance. Same units as data.

Box plot (box-and-whisker) shows?

5-number summary: min, Q1, median, Q3, max.

WORKED EXAMPLE: Build a frequency distribution for test scores {62, 75, 68, 88, 91, 73, 79, 65, 82, 95, 78, 70} using bins of width 10 starting at 60. Then interpret the histogram shape.

Step 1 — DEFINE BINS: [60-69], [70-79], [80-89], [90-99]. Step 2 — COUNT each bin: 60-69: {62, 68, 65} → 3 70-79: {75, 73, 79, 78, 70} → 5 80-89: {88, 82} → 2 90-99: {91, 95} → 2 Step 3 — VERIFY TOTAL: 3+5+2+2 = 12 ✓. Step 4 — RELATIVE FREQ: 3/12=25%, 5/12≈42%, 2/12≈17%, 2/12≈17%. Step 5 — INTERPRET histogram: tallest bar at 70-79; slightly right-skewed (tail extends to higher scores); modal class is 70-79. Step 6 — APPLY: the largest group (5 of 12) scored in the 70s; the few high scores pull the mean above the median.

Practise the full chapter

These are a sample. The full Describing Data with Numbers and Graphs chapter runs 65 items with per-chapter progress tracking, on the web and in the iOS app.

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