AP (Advanced Placement) · AP Statistics

Data, Probability and Inference

25 practice questions, each with the answer and an explanation.

Practise Data, Probability and Inference now

Random questions from this topic, one at a time. You see the answer and the explanation straight after each one.

All 25 questions

  1. Which measure of center is least affected by extreme values in a data set?
  2. A data set is skewed to the right. Which statement about its mean and median is most likely true?
  3. Heights of adult men are approximately normally distributed with a mean of 70 inches and a standard deviation of 3 inches. About what percent of men are between 64 and 76 inches tall?
  4. A z-score of -1.5 for a test score means that the score is what?
  5. A correlation coefficient of r = -0.9 between two variables indicates what?
  6. In the regression equation y-hat = 5 + 2x, what does the slope of 2 mean?
  7. A researcher numbers all students in a school, picks a random starting point and then selects every tenth student. What type of sample is this?
  8. A survey about a new park is mailed to residents, and only those who feel strongly respond. Which problem is most likely?
  9. In a study, people who drink coffee have a lower rate of a disease, but coffee drinkers also exercise more. What is exercise called in this study?
  10. What is the purpose of random assignment in an experiment?
  11. A fair six-sided die is rolled twice. What is the probability that the sum of the two rolls is 7?
  12. Events A and B are independent with P(A) = 0.4 and P(B) = 0.5. What is P(A and B)?
  13. A 95 percent confidence interval for a population mean is (42, 48). Which interpretation is correct?
  14. A hypothesis test gives a p-value of 0.03. What does this mean?
  15. What is a Type I error in a hypothesis test?
  16. Which graph is best for showing the shape of a distribution of a single quantitative variable?
  17. Increasing the sample size while keeping everything else the same has what effect on the width of a confidence interval?
  18. Which statistic measures the typical distance of data values from the mean?
  19. A residual plot for a linear regression shows a clear curved pattern. What does this suggest?
  20. Which condition is required before using a chi-square test for independence on a two-way table?
  21. A sampling distribution describes what?
  22. What does the Central Limit Theorem say about the sampling distribution of the sample mean?
  23. If the correlation between two variables is r = 0.8, what percent of the variation in y is explained by the linear relationship with x?
  24. A coin is flipped 10 times and lands heads 5 times. A student says tails must come up next because it is 'due'. What is wrong with this thinking?
  25. Which of the following is a parameter rather than a statistic?

Keep practising

More AP (Advanced Placement) topics

All AP (Advanced Placement) practice →

Ready for the full AP (Advanced Placement) test?

Take a mock testAP (Advanced Placement) hub