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8 multiple-choice questions and 37 flashcards on Probability: Rules, Conditional, Independence, about 5% of the HS Statistics bank. Every one carries a written rationale.
Probability: Rules, Conditional, Independence is one of 7 chapters in CoStudy's HS Statistics bank, and it holds 8 of the bank's 150 multiple-choice questions — roughly 5% 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.
1 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.
What does a P-VALUE represent in hypothesis testing?
Answer: D — Probability of observing the test result (or more extreme) IF the null hypothesis is true
P-value: conditional probability — if H₀ is true, how likely is data this extreme? Small p (typically < 0.05) → reject H₀. NOT 'probability H₀ true' (common misconception). Foundation of inference.
4 cards from the 37 in this chapter.
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: most students scored in the C range; the few high scores pull the mean above the median.
Simple random sample?
Each member of population has equal chance of selection.
Dot plot?
Each data point a dot above a number line. Good for small data sets.
Histogram?
Bar graph of frequency distribution for quantitative data. Reveals shape, center, spread.
These are a sample. The full Probability: Rules, Conditional, Independence chapter runs 45 items with per-chapter progress tracking, on the web and in the iOS app.
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