Descriptive Statistics Numerical Ch1 (1-33)

Descriptive Statistics: Numerical Multiple Choice 1. Geometric mean is a measure of a. location. b. dispersion. c. variability. d. weight. a ANSWER: 2. Growth factors for the population of Chattanooga in the past two years have been 8 and 12. The geometric mean has a value of a. 20. b. . c. . d. 96. ANSWER: c 3. Growth factors for the population of Atlanta in the past five years have been 1, 2, 3, 4 , and 5. The geometric mean is a. 15. b. . c. . d. . ANSWER: d 4. The geometric mean of five observations is the a. same as their weighted mean. b. same as their mean. c. square root of the product of the 5 observations. d. fifth root of the product of the 5 observations. d ANSWER: 5. The nth root of the product of the n observations is the a. weighted mean. b. geometric mean. c. product deviation. d. product variance. b ANSWER: 6. The measure of location which is the most likely to be influenced by extreme values in the data set is the a. range. b. median. c. mode. d. mean. d ANSWER: 7. If two groups of numbers have the same mean, then a. their standard deviations must also be equal. b. their medians must also be equal. c. their modes must also be equal. d. other measures of location need not be the same. ANSWER: d 8. The mean of the sample a. is always smaller than the mean of the population from which the sample was taken. b. can never be zero. c. can never be negative. d. can assume any value between the highest and the lowest value in the sample. d ANSWER: 9. When a percentage of the smallest and largest values are deleted from a data set, the mean of the remaining data values is the a. geometric mean. b. weighted mean. c. trimmed mean. d. interquartile mean. c ANSWER: 10. Which of the following provides a measure of central location for the data? a. Standard deviation b. Mean c. Variance d. Range b ANSWER: 11. In computing the mean of a sample, the value of ∑xi is divided by a. n. b. n - 1. c. n + 1. d. n - 2. ANSWER: a 12. A numerical value used as a summary measure for a sample, such as sample mean, is known as a a. population parameter. b. sample parameter. c. sample statistic. d. population mean. c ANSWER: 13. μ is an example of a a. population parameter. b. sample statistic. c. population variance. d. mode. a ANSWER: 14. The mean of a sample a. is always equal to the mean of the population. b. is always smaller than the mean of the population. c. is computed by summing the data values and dividing the sum by (n - 1). d. is computed by summing all the data values and dividing the sum by the number of items. ANSWER: d 15. The hourly wages of a sample of 130 system analysts are given below. mean = 60 mode = 73 median = 74 range = 20 variance = 324 The coefficient of variation equals a. 0.30%. b. 30%. c. 5.4%. d. 54%. ANSWER: b 16. The variance of a sample of 169 observations equals 576. The standard deviation of the sample equals a. 13. b. 24. c. 576. d. 28,561. b ANSWER: 17. The median of a sample will always equal the a. (Q1 + Q3)/2. b. Q4/2. c. 50th percentile. d. (smallest value + largest value)/2. ANSWER: c 18. The median is a measure of a. relative dispersion. b. absolute dispersion. c. central location. d. relative location. c ANSWER: 19. The 50th percentile is the a. mode. b. median. c. mean. d. third quartile. b ANSWER: 20. The 75th percentile is referred to as the a. first quartile. b. second quartile. c. third quartile. d. fourth quartile. c ANSWER: 21. The pth percentile is a value such that approximately a. p percent of the observations are less than the value and (100 - p) percent are more than this value. b. p percent of the observations are less than the value and p percent are more than this value. c. (100 - p) percent of the observations are less than the value and p percent are more than this value. d. (100 - p) percent of the observations are less than the value and (100 - p) percent are more than this value. a ANSWER: 22. The difference between the largest and the smallest data values is the a. variance. b. interquartile range. c. range. d. coefficient of variation. c ANSWER: 23. The first quartile a. contains at least one third of the data elements. b. is the same as the 25th percentile. c. is the same as the 50th percentile. d. is the same as the 75th percentile. ANSWER: b 24. When computing the mean, the smallest value a. can never be negative. b. can never be zero. c. can never be less than the mean. d. can be any value. d ANSWER: 25. Which of the following is not a measure of central location? a. Mean b. Median c. Variance d. Mode c ANSWER: 26. If a data set has an even number of observations, the median a. cannot be determined. b. is the average value of the two middle items. c. must be equal to the mean. d. is the average value of the two middle items when all items are arranged in ascending order. d ANSWER: 27. Which of the following is a measure of variability? a. Percentiles b. Quartiles c. Interquartile range d. Geometric mean ANSWER: c 28. The value which has half of the observations above it and half the observations below it is called the a. range. b. median. c. mean. d. mode. b ANSWER: 29. The most frequently occurring value of a data set is called the a. range. b. mode. c. mean. d. median. b ANSWER: 30. The interquartile range is a. the 50th percentile. b. another name for the variance. c. the difference between the largest and smallest values. d. the difference between the third quartile and the first quartile. ANSWER: d 31. The weights (in pounds) of a sample of 36 individuals were recorded and the following statistics were calculated. mean = 160 range = 60 mode = 165 variance = 324 median = 170 The coefficient of variation equals a. 0.1125%. b. 11.25%. c. 203.12%. d. 0.20312%. ANSWER: b 32. The heights (in inches) of 25 individuals were recorded and the following statistics were calculated mean = 70 range = 20 mode = 73 variance = 784 median = 74 The coefficient of variation equals a. 11.2%. b. 1120%. c. 0.4%. d. 40%. d ANSWER: 33. The standard deviation of a sample of 100 observations equals 64. The variance of the sample equals a. 8. b. 10. c. 6400. d. 4,096. d ANSWER: