AP Statistics

Midterm Exam Review

  1. Classify as qualitative or quantitative.
  1. married or not married
  2. number of books in your locker
  3. rocks divided into categories
  4. weight of a rock
  5. zip codes
  1. Classify as Continuous or Discrete
  1. weight of your books
  2. number of tv’s you own
  3. time it takes to run the 50
  4. number of races won
  1. Classify the type of sampling as being either cluster, systematic, convenience, random, or stratified.
  1. we will survey every 5th person who comes in the door.
  2. Put all the names in a hat and draw out 5 names
  3. We will survey everyone in two of the schools out of the district
  4. Survey the first 5 people I see because I don’t have much time
  5. Separate everyone according to eye color and then choose 4 from each group.
  1. During July, a private pool recorded the weights of 30 males in its water aerobics class.

143156156163167

142171170169164

138158160162164

173157158159160

138172166166159

120125165136168

  1. Construct a frequency distribution for the data. Use six classes.
  1. Construct a histogram.
  1. The number of vehicles passing a tollgate between 7 am and 8 am were recorded for twenty different days.

10 26 32 15 16 22 31

46 27 33 27 15 16 19

20 16 12 22 30 41

  1. Construct a stem & leaf
  2. Find the mean
  3. Find the median
  4. Find the mode.
  5. Construct the box plot
  6. Find the variance
  7. Find the standard deviation.
  8. Are there any outliers? Show your work.
  1. If , , and , what is the z-score. What does it mean?
  1. The diastolic blood pressure x, and the systolic blood pressure, y, were recorded for 13 females.
  1. Find the correlation coefficient.
  2. Find the linear regression line.
  3. What is the predicted value of y for x = 65?
  4. What percent of variation in systolic blood pressure can be explained by the least squares line?
  5. What is the residual value for a diastolic blood pressure of 90?

8. In a survey of high school students, 25 said that they have cheated on a test and 14 said they have not cheated. What is the probability that a student chosen at random has cheated?

9. What is the probability of drawing a king or a diamond from a deck of cards?

10. What is the probability of drawing a king and then another king on the second draw if there is no replacement?

11. A question has 4 multiple choice answers.

  1. Find the probability of guessing an incorrect answer.
  2. If there are 5 questions, what's the probability of getting all 5 correct?

12. The probability of being a college graduate is 18%. If 5 people are asked if they graduated from college, what is the probability that 3 people were asked before a college graduate was found?

13. The results of a survey are shown below.

  1. Find the probability of selecting a male.
  2. Find the probability of a yes or a maybe.
  3. Find the probability of a female and a yes.
  4. Find the probability of being a male, given that the answer was no.
  5. Find the probability of a no or female.

14. Given the following probability distribution, find the following.

  1. mean
  2. standard deviation
  3. Probability that x is within 1 standard deviation of the mean.

15. If 60% of all women are employed outside the home, find the probability that in a sample of 20 women,

  1. Exactly 15 are employed.
  2. At least 10 are employed.

16. If 80% of the applicants are able to pass a driver's proficiency road test, find the mean, variance, and standard deviation of the number of people who pass the test in a sample of 300 applicants.

17. The mean score on a standardized test is 120 with a standard deviation of 14.

  1. What is the probability of a student scoring at most a 103?
  2. What is the probability of a student making between a 110 and 125?
  3. What is the cutoff score for the top 10% of the grades?
  4. If a sample of 100 scores are analyzed, what’s the probability that the sample mean is at least 121?

18. Just before a referendum on a school budget, a local newspaper polls 400 voters in an attempt to predict whether the budget will pass. Suppose that the budget actually has the support of 52% of the voters. What's the probability the newspaper's sample will be less than 50%?

19. A bottling machine is operating with a standard deviation of 0.12 ounces. Suppose that in a SRS of 36 bottles, the machine inserted an average of 16.1 ounces into each bottle. Find & interpret a 90% confidence interval for the mean amount in each bottle.

20. Ball bearings are manufactured by a process that results in a standard deviation in diameter of 0.025 inch. What sample size should be chosen if we wish to be 99% sure of knowing the diameter to within 0.01 inch?

21. In a SRS of machine parts, 18 out of 225 were found to have been damaged in shipment. Find a 95% confidence interval for the proportion of machine parts that are damaged in shipment.

22. How many executives should be interviewed if an estimate is desired at the 99% confidence level to be within 0.06 of the true proportion of executives who believe their workers need more vacation time?