STAT151 Study Guide - Midterm Guide: Confidence Interval, Quartile, Standard Deviation
Statistics 151 Practice Midterm 1 – Mike Kowalski
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Statistics 151 Practice Midterm 1 – Multiple Choice (50 minutes)
Instructions:
1. This is a closed book exam.
2. You may use the STAT 151 formula sheets and tables provided and a NON-PROGRAMMABLE calculator only.
3. You have 50 minutes to complete the exam.
4. The exam consists of 25 multiple choice questions worth 1 mark each.
5. Topics covered: Chapters 1 – 8 in Agresti/Franklin 2.
1. The fraction of the variation in the values of a response y that is explained by the least-squares regression of y on x is
A) the correlation coefficient.
B) the slope of the least-squares regression line.
C) the square of the correlation coefficient.
D) the intercept of the least-squares regression line.
Use the following to answer the questions 2 - 3.
A sample was taken of the verbal GRE scores of 20 applicants to graduate school at a large midwestern university. Below are
the scores. For convenience, the data are ordered.
280 310 340 350 370 410 420 420 420 470
490 510 520 520 600 610 670 720 750 770
2. The first quartile for the applicant scores is
A) 340.
B) 390.
C) 480.
D) 605.
3. If 25 points were added to each score, then the standard deviation of the new scores would
A) be increased by 5.
B) be increased by 25.
C) be increased by 625.
D) remain unchanged.
4. A newspaper conducted a statewide survey concerning a proposal to raise taxes in order to prevent budget
cuts to education. The newspaper took a random sample (assume it is an SRS) of 1200 registered voters
and found that 580 would vote to raise taxes. Let p represent the proportion of registered voters in the
state that would vote to raise taxes. A 90% confidence interval for p is
A) 0.483 ± 0.014.
B) 0.483 ± 0.024.
C) 0.483 ± 0.028.
D) 0.483 ± 0.249.
5. In a certain town 60% of the households own mutual funds, 40% own individual stocks, and 20% own both mutual
funds and individual stocks. The proportion of households that own neither mutual funds nor individual stocks is
A) 20%.
B) 30%.
C) 40%.
D) 50%.
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6. A researcher reports that, on average, the participants in his study lost 10.4 lbs. after two months on his new diet. A
friend of yours comments that she tried the diet for two months and lost no weight, so clearly the report must be a
fraud. Which of the following statements is correct?
A) Your friend must not have followed the diet correctly because she did not lose weight.
B) Because your friend did not lose weight, the report must not be correct.
C) The report gives only the average. This does not imply that all participants in the study lost 10.4 lbs. or even that all
participants lost weight. Your friend's experience does not necessarily contradict the study results.
D) In order for the study to be correct, we must now add your friend's results to those of the study and re-compute the
new average.
7. In a large population of adults, the mean IQ is 112 with a standard deviation of 20. Suppose 200 adults are randomly
selected for a market research campaign. The probability that the sample mean IQ is greater than 110 is
A) 0.079.
B) 0.421.
C) 0.921.
D) 0.579.
Use the following to answer the questions 8 - 9.
A sample was taken of the salaries of 20 employees of a large company. The following is a boxplot of the salaries (in
thousands of dollars) for this year.
80
70
60
50
40
30
8. Based on this boxplot, the five-number summary is
A) 28, 39, 48, 60.5, 77.
B) 28, 41, 48, 58, 77.
C) 28, 39, 51, 58, 77.
D) 28, 41, 51, 60.5, 77.
9. Based on this boxplot, which of the following statements is true?
A) The salary distribution is fairly symmetric.
B) About 10 employees make over $50,000.
C) Nobody makes over $80,000.
D) All of the above.
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STAT151 Full Course Notes
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Document Summary
Statistics 151 practice midterm 1 mike kowalski. Statistics 151 practice midterm 1 multiple choice (50 minutes) You may use the stat 151 formula sheets and tables provided and a non-programmable calculator only. You have 50 minutes to complete the exam. The exam consists of 25 multiple choice questions worth 1 mark each. Topics covered: chapters 1 8 in agresti/franklin 2. Use the following to answer the questions 2 - 3. A sample was taken of the verbal gre scores of 20 applicants to graduate school at a large midwestern university. The first quartile for the applicant scores is: 340, 390, 480, 605. If 25 points were added to each score, then the standard deviation of the new scores would: be increased by 5, be increased by 25, be increased by 625, remain unchanged. A newspaper conducted a statewide survey concerning a proposal to raise taxes in order to prevent budget cuts to education.
