Name: ______5) Suppose the average height of policemen is 71 inches with a standard AP Statistics deviation of 4 inches, while the average height for policewomen is 66 inches with a standard deviation of 3 inches. If a committee looks at all AP Review – Center, Spread, Boxplots ways of pairing up on male with one female officer, what will be the mean and standard deviation for the difference in heights for the set of 1) Suppose the average score on a national test is 500 with a standard possible partners? deviation of 100. If each score is increased by 25, what are the new A) Mean of 5 inches with a standard deviation of 1 inch mean and standard deviation? B) Mean of 5 inches with a standard deviation of 3.5 inches A) 500, 100 D) 525, 105 C) Mean of 5 inches with a standard deviation of 5 inches B) 500, 125 E) 525, 125 D) Mean of 68.5 inches with a standard deviation of 1 inch C) 525, 100 E) Mean of 68.5 inches with a standard deviation of 3.5 inches

2) Suppose the average score on a national test is 500 with a standard 6) Consider these parallel boxplots of gasoline mileage for three makes deviation of 100. If each score is increased by 25%, what are the new of cars. Which of the following are true statements? mean and standard deviation? A) 500, 100 D) 625, 105 B) 525, 100 E) 625, 125 C) 625, 100

3) In a certain southwestern city the air pollution index averages 62.5 22 24 26 28 30 Miles per gallon during the year with a standard deviation of 18. Assuming that the empirical rule is appropriate, the index falls within what interval 95% of I. All three have the same range. the time? II. All three have the same interquartile range. A) (8.5, 116.5) D) (45.4, 79.6) III. The difference in the medians between the first and third B) (26.5, 98.5) E) There is insufficient distributions is equal to the interquartile range of the second C) (44.5, 80.5) information to answer this question. distribution. A) I and II B) I and III 4) The average cost per ounce for glass cleaner is 7.7 cents with a C) II and III standard deviation of 2.5 cents. What is the z-score of Windex with a D) I, II, and III cost of 10.1 cents per ounce? E) None of the above gives the complete set of true responses. A) 0.96 D) 4.04 B) 1.31 E) None of these C) 1.94 7) When a set of data has suspect outliers, which of the following are 11) The 1992 NAEP Trial State Assessment calculated a state-by-state preferred measures of central tendency and of variability? average mathematics proficiency score for students in the eighth grade. A) mean and standard deviation The resulting boxplot is below. Which of the following statements are B) mean and variance true? C) mean and range 280 D) median and range E) median and interquartile range 270

260 8) If the standard deviation as a set of observations is 0, you can conclude 250 A) that there is no relationship between the observations. B) that the average value is 0. C) that all the observations are the same value. I. The state score 273 has a percentile rank of 75. D) that a mistake in arithmetic has been made. II. The mean state score is 270. E) none of the above. III. The lowest state score is 245. A) III only B) I and II 9) A teacher is teaching two AP Statistics classes. On the final exam, C) I and III the 20 students in the first class averaged 92 while the 25 students in D) II and III the second class averaged only 83. If the teacher combines the classes, E) I, II, and III what will the average final exam score be? A) 87 B) 87.5 12) A survey was conducted to gather ratings of the quality of service at C) 88 a local restaurant. Respondents were to rate overall service using the D) 85 values between 0 (terrible) and 100 (excellent). The ratings are: E) There is insufficient information to answer this question. Stem Leaf The value 82 is 3 2 4 A) the maximum but not an outlier 4 0 3 4 7 8 9 9 9 10) Suppose X and Y are random variables with μX  10, σX  3, μY  15, B) the maximum and an outlier 5 0 1 1 2 3 4 5 and σY  4. Given that X and Y are independent, what are the mean and C) one of two outliers 6 1 2 5 6 6 8 standard deviation of the random variable X + Y? D) not a data value 7 μ  25, σ  3.5 E) none of these. A) X Y X Y 8 0 2 B) μX Y  25, σX Y  5 Stem: tens μ  25, σ  7 C) X Y X Y Leaf: ones D) μX Y  12.5, σX Y  7 E) There is insufficient information to answer this question.