Class: Date: Unit 2 Test Review Find the mean, median, and mode of the data set. Round to the nearest tenth. 1. 4, 7, 8, 15, 1, 7, 8, 14, 7, 15, 4 a. mean = 7.5, median = 7, mode = 7 b. mean = 8.2, median = 7, mode = 7 c. mean = 8.2, median = 8, mode =7 d. mean = 7.5, median = 7, mode = 8 2. test scores on a math exam: 82, 78, 72, 72, 94, 62, 93, 62, 100, 88, 72, 90, 86, 66, 98, 78, 76, 85, 67, 97, 67, 68 a. mean = 79.7, median = 78, mode = 72 b. mean = 73, median = 78, mode = 81 c. mean = 79.7, median = 81, mode = 72 d. mean = 73, median = 78, mode = 72 Find the outlier in the set of data. 3. 4.4, 3.5, 6.7, 0.8, 4.9, 3.8, 5.3, 5.1 a. 4.9 b. 5.3 c. 0.8 d. 6.7 4. 13, 12, 34, 21, 14, 10, 15, 22 a. 10 b. 34 c. 21 d. 12 5. Over the first five years of owning her car, Gina drove about 12,700 miles the first year, 6,909 miles the second year, 12,675 the third year, 11,000 the fourth year, and 12,725 the fifth year. a. Find the mean, median, and mode of this data. b. Explain which measure of central tendency will best predict how many miles Gina will drive in the sixth year. a. mean = 11,202; median = 12,675; no mode; the median is the best choice because it is not skewed by the low outlier. b. mean = 12,675; median = 11,202; no mode; the mean is the best choice because it is representative of the entire data set. c. mean = 11,202; median = 12,675; mode = 5,816; the median is the best choice because it is not skewed by the low outlier. d. mean = 11,202; median = 12,675; no mode; the mean is the best choice because it is representative of the entire data set. 1
Make a box-and-whisker plot of the data. 6. 28, 16, 21, 14, 25, 13, 16, 26 a. b. c. d. 7. Average daily temperatures in Tucson, Arizona, in December: 53, 64, 52, 54, 50, 55, 58, 58, 65, 65, 61, 58, 57, 64, 65, 58, 53, 52, 59, 64 a. b. c. d. What are the mean, variance, and standard deviation of these values? Round to the nearest tenth. 8. 10, 7, 14, 13, 4, 11 a. mean = 10.5 variance = 1.9; standard deviation = 3.4 b. mean = 9.8 variance = 11.8; standard deviation = 3.4 c. mean = 9.8 variance = 1.9; standard deviation = 3.8 d. mean = 10.5 variance = 11.8; standard deviation = 3.8 2
9. 52, 63, 92, 56, 52, 86 a. mean = 59.5 variance = 262.1; standard deviation = 17.7 b. mean = 66.8 variance = 262.1; standard deviation = 16.2 c. mean = 66.8 variance = 4; standard deviation = 16.2 d. mean = 59.5 variance = 4; standard deviation = 17.7 10. x x x (x x) 2 21 19.4 376.4 50 9.6 92.2 53 12.6 158.8 32 8.4 70.6 46 5.6 31.4 a. mean = 40.4 variance = 704.1 standard deviation = 12.1 b. mean = 165.2 variance = 145.8 standard deviation = 12.1 c. mean = 40.4 variance = 145.8 standard deviation = 21269.3 d. mean = 40.4 variance = 145.8 standard deviation = 12.1 Use a calculator to find the mean and standard deviation of the data. Round to the nearest tenth. 11. 20, 19, 13, 16, 10, 11, 17 a. mean = 16; standard deviation = 3.6 b. mean = 15.1; standard deviation = 13 c. mean = 15.1; standard deviation = 3.6 d. mean = 16; standard deviation = 13 12. 401, 451, 217, 571, 957, 833, 773, 420, 104, 475, 856, 883 a. mean = 578.4; standard deviation = 266.9 c. mean = 578.4; standard deviation = 71256.2 b. mean = 523; standard deviation = 71256.2 d. mean = 523; standard deviation = 266.9 13. The height (in feet) of a sample of trees in the school playground: 12.5, 9.8, 13.5, 11.2, 12.3, 14.2, 11.7, 9.8, 12.6, 10.4 a. mean = 11.8 ft; standard deviation = 1.43 ft c. mean = 11.8 ft; standard deviation = 4.52 ft b. mean = 13.1 ft; standard deviation = 1.43 ft d. mean = 13.1 ft; standard deviation = 4.52 ft 3
14. Susan keeps track of the number of tickets sold for each play presented at The Community Theater. Within how many standard deviations from the mean do all the values fall? 159, 151, 91, 126, 64, 152, 138, 129, 78, 78, 160, 84 a. 3 b. 2 c. 5 d. 4 15. Mrs. Jones Algebra 2 class scored very well on yesterday s quiz. With one exception, everyone received an A. Within how many standard deviations from the mean do all the quiz grades fall? 91, 92, 94, 88, 96, 99, 91, 93, 94, 97, 95, 97 a. 2 b. 1 c. 3 d. 4 16. The graph below displays how many pieces of candy Timmy and his five friends each received last Halloween. Within how many standard deviations of the mean do the values fall? a. 3 b. 4 c. 1 d. 2 17. The scores on an exam are normally distributed, with a mean of 80 and a standard deviation of 5. What percent of the scores are greater than 85? a. 84% b. 68% c. 16% d. 2.5% The bar graph shows the rents paid per month for apartments in an urban neighborhood. The curve shows that the rents are normally distributed. 18. Estimate the percent of apartment residents who pay from $600 to $749 per month. a. 93% b. 68% c. 43% d. 25% 19. Estimate the percent of apartment residents who pay less than $600 per month. a. 99% b. 25% c. 68% d. 3% 4
20. The average height of corn stalks in a field is 71 inches with a standard deviation of 1.3 inches. Sketch a normal curve labeling the horizontal axis at one, two, and three standard deviations from the mean. 21. A grocery store will only accept yellow onions that are at least 3.25 in. in diameter. A grower has a crop of onions with diameters that are normally distributed, with a mean diameter of 3 in. and a standard deviation of 0.25 in. What percent of the onions will be accepted by the grocery store? a. 16% b. 2.5% c. 50% d. 84% 22. The numbers of cookies in a shipment of bags are normally distributed, with a mean of 48 and a standard deviation of 3. What percent of bags of cookies will contain between 42 and 54 cookies? a. 16% b. 47.5% c. 2.5% d. 95% 23. The scores on a final exam were approximately normally distributed with a mean of 82 and a standard deviation of 11. If 85 students took the exam, and above a 60 is a passing grade, how many students failed the exam? a. 13 c. 12 b. 1 d. 2 24. You took a test last week and the average grade was a 85. The standard deviation was 3.1 points. Sketch a normal curve labeling the horizontal axis at one, two, and three standard deviations from the mean. 25. Sketch a normal curve with a mean of 50 and a standard deviation of 3. Label the horizontal axis at one, two, and three standard deviations from the mean. 5
Unit 2 Test Review [Answer Strip] B 9. 14. B B 1. B 6. 15. A 21. A A 2. 10. D 16. D 22. D 23. D C 3. B 4. A 7. 17. C A 5. 11. C 12. A B 8. 13. A 18. A 19. D