Business Stat 2300 KSU

47. The coefficient of correlation ranges between a. 0 and 1 b. -1 and +1 c. minus infinity and plus infinity d. 1 and 100

-1 and +1

40. Which of the following symbols represents the mean of the sample? a. σ2 b. σ c. μ d. -x

-x

Scenario 2: A researcher has collected the following five data points. 3 5 12 3 2 60. Refer to scenario 2. The range is a. 1 b. 2 c. 10 d. 12

10

Scenario 2: A researcher has collected the following five data points. 3 5 12 3 2 57. Refer to scenario 2. The variance is a. 80 b. 4.062 c. 13.2 d. 16.5

16.5

Scenario 2: A researcher has collected the following five data points. 3 5 12 3 2 61. Refer to scenario 2. The interquartile range is a. 1 b. 2 c. 10 d. 12

2

Scenario 2: A researcher has collected the following five data points. 3 5 12 3 2 58. Refer to scenario 2. The standard deviation is a. 8.944 b. 4.062 c. 13.2 d. 16.5

4.062

Scenario 1: A researcher has collected the following sample data 5 12 6 8 5 6 7 5 12 4 54. Refer to scenario 1. The mode is a. 5 b. 6 c. 7 d. 8

5

the median of a sample will always equal the a. mode b. mean c. 50th percentile d. all of the above answers are correct

50th percentile

Scenario 1: A researcher has collected the following sample data 5 12 6 8 5 6 7 5 12 4 53. Refer to scenario 1. The median is a. 5 b. 6 c. 7 d. 8

6

Scenario 1: A researcher has collected the following sample data 5 12 6 8 5 6 7 5 12 4 55. Refer to scenario 1. The mean is a. 5 b. 6 c. 7 d. 8

7

Scenario 1: A researcher has collected the following sample data 5 12 6 8 5 6 7 5 12 4 56. Refer to scenario 1. The 75th percentile is a. 5 b. 6 c. 7 d. 8

8

Scenario 2: A researcher has collected the following five data points. 3 5 12 3 2 59. Refer to scenario 2. The coefficient of variation is a. 72.66% b. 81.24% c. 264% d. 330%

81.24

65. If you are told a population has a mean of 25 and a variance of 0,what must you conclude? a. Someone has made a mistake. b. There is only one element in the population. c. There are no elements in the population. d. All the elements in the population are 25. e. None of the above

All the elements in the population are 25.

39. Which of the following symbols represents the size of the population? a. σ2 b. σ c. μ d. N

N

34. 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. None of these alternatives is correct

None of these alternatives is correct

52. Since the mode is the most frequently occurring data value, it a. can never be larger than the mean b. is always larger than the median c. is always larger than the mean d. None of these alternatives is correct.

None of these alternatives is correct.

5. μ is an example of a a. population parameter b. sample statistic c. population variance d. mode

a population parameter

1. "In samples we deal with _____ , in populations with _____ ." a. statistics, parameters b. parameters, statistics c. statistics, statistics d. Parameters, parameters

a. statistics, parameters

35. The sum of deviations of the individual data elements from their mean is a. always greater than zero b. always less than zero c. sometimes greater than and sometimes less than zero, depending on the data elements d. always equal to zero

always equal to zero

7. The variance of a sample of 169 observations equals 576. The standard deviation of the sample equals a. 13 b. 24 c. 576 d. 28,461

b. 24

6. The hourly wages of a sample of 130 system analysts are given below. mean = 60 range = 20 mode = 73 variance = 324 median = 74 The coefficient of variation equals a. 0.30% b. 30% c. 5.4% d. 54%

b. 30%

2. Which of the following provides a measure of central location for the data? a. standard deviation b. mean c. variance d. range

b. mean

4. Since the population size is always larger than the sample size, then the sample statistic a. can never be larger than the population parameter b. can never be equal to the population parameter c. can be smaller, larger, or equal to the population parameter d. can never be smaller than the population parameter

c. can be smaller, larger, or equal to the population parameter

3. A numerical value used as a summary measure for a sample, such as sample mean, is known as a a. sample slapstick b. sample sadistic c. sample statistic d. sample static

c. sample statistic

48. The coefficient of correlation a. is the same as the coefficient of determination b. can be larger than 1 c. cannot be larger than 1 d. cannot be negative

cannot be larger than 1

9. The median is a measure of a. relative dispersion b. absolute dispersion c. central location d. relative location

central location

46. A numerical measure of linear association between two variables is the a. variance b. coefficient of variation c. correlation coefficient d. standard deviation

correlation coefficient

32. The sample variance a. is always smaller than the true value of the population variance b. is always larger than the true value of the population variance c. could be smaller, equal to, or larger than the true value of the population variance d. can never be zero

could be smaller, equal to, or larger than the true value of the population variance

44. A numerical measure of linear association between two variables is the a. variance b. covariance c. standard deviation d. coefficient of variation

covariance

25. In computing descriptive statistics from grouped data (like a frequency histogram), a. data values are treated as if they occur at the midpoint of a class b. the grouped data result is more accurate than the ungrouped result c. the grouped data computations are used only when a population is being analyzed d. None of these alternatives is correct.

data values are treated as if they occur at the midpoint of a class

62. The average age of students at KSU increased from 22 with a standard deviation of 3.96 to an average age of 24 with a standard deviation of 4.08. The relative dispersion around the mean a. Decrease b. Increase c. Stayed the dame d. Disappeared

decrease

21. When data are positively skewed, the mean will usually be a. greater than the median b. smaller than the median c. equal to the median d. positive

greater than the median

16. Which of the following is a measure of dispersion? a. percentiles b. quartiles c. interquartile range d. all of the above are measures of dispersion

interquartile range

15. 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

is the average value of the two middle items when all items are arranged in ascending order

13. 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

is the same as the 25th percentile

67. In a group of 12 scores, the largest score is increased by 36 points. What effect will this have on the mean of the scores? a. it will be increased by 12 points b. it will remain unchanged c. it will be increased by 3 points d. it will increase by 36 points e. there is no way of knowing exactly how many points the mean will be increased.

it will be increased by 3 points

11. The pth percentile is a value such that at least p percent of the observations are a. less than or equal to this value b. less than this value c. more than or equal to this value d. more than this value

less than or equal to this value

29. 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

mean

30. The most important statistical descriptive measure of the location of a data set is the a. mean b. median c. mode d. variance

mean

17. The most frequently occurring value of a data set is called the a. range b. mode c. mean d. median

mode

51. Which of the following is not a measure of dispersion? a. mode b. standard deviation c. range d. interquartile range

mode

50. During a cold winter, the temperature stayed below zero for ten days (ranging from -20 to -5). The variance of the temperatures of the ten day period a. is negative since all the numbers are negative b. must be at least zero c. cannot be computed since all the numbers are negative d. can be either negative or positive

must be at least zero

41. Which of the following symbols represents the size of the sample a. σ2 b. σ c. N d. n

n

31. The numerical value of the standard deviation can never be a. larger than the variance b. zero c. negative d. smaller than the variance

negative

33. The variance can never be a. zero b. larger than the standard deviation c. negative d. smaller than the standard deviation

negative

64. The mean of the population of ten scores, 78, 91, 91, 94, 74, 23, 63, 22, 78, 89 is 70.3, and the modes are 78 and 91. The skewness of the population is: a. negative b. zero c. positive d. not determined e. positive or negative depending on the score.

negative

27. When should measures of location and dispersion be computed from grouped data rather than from individual data values? a. as much as possible since computations are easier b. only when individual data values are unavailable c. whenever computer packages for descriptive statistics are unavailable d. only when the data are from a population

only when individual data values are unavailable

20. When the data are skewed to the right, the measure of Skewness will be a. negative b. zero c. positive d. one

positive

45. Positive values of covariance indicate a. a positive variance of the x values b. a positive variance of the y values c. the standard deviation is positive d. positive relation between the independent and the dependent variables

positive relation between the independent and the dependent variables

12. The difference between the largest and the smallest data values is the a. variance b. interquartile range c. range d. coefficient of variation

range

19. If index i (which is used to determine the location of the pth percentile) is not an integer, its value should be a. squared b. divided by (n - 1) c. rounded down d. rounded up

rounded up

66. If the mean, median and mode of a distribution are 5, 6, 7 respectively, then the distribution is: a. skewed negatively b. not skewed c. skewed positively d. symmetrical e. bimodal.

skewed negatively

22. Which of the following is not a measure of dispersion? a. the range b. the 50th percentile c. the standard deviation d. the interquartile range

the 50th percentile

24. If the variance of a data set is correctly computed with the formula using n - 1 in the denominator, which of the following is true? a. the data set is a sample b. the data set is a population c. the data set could be either a sample or a population d. the data set is from a census

the data set is a sample

18. 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

the difference between the third quartile and the first quartile

63. A measure of location that is calculated by finding the nth root of the product of the n values is known as a. square root mean b. mean square root c. mean square error d. the Geometric mean

the geometric mean

26. The measure of dispersion that is influenced most by extreme values is a. the variance b. the standard deviation c. the range d. the interquartile range

the range

23. The interquartile range is used as a measure of variability to overcome what difficulty of the range? a. the sum of the range variances is zero b. the range is difficult to compute c. the range is influenced too much by extreme values d. the range is negative

the range is influenced too much by extreme values

28. The descriptive measure of dispersion that is based on the concept of a deviation about the mean is a. the range b. the interquartile range c. the absolute value of the range d. the standard deviation

the standard deviation

42. The symbol σ is used to represent a. the variance of the population b. the standard deviation of the sample c. the standard deviation of the population d. the variance of the sample

the standard deviation of the population

49. When the smallest and largest percentage of items are removed from a data set and the mean is computed, the mean of the remaining data is a. the median b. the mode c. the trimmed mean d. any of the above

the trimmed mean

43. The symbol σ2 is used to represent a. the variance of the population b. the standard deviation of the sample c. the standard deviation of the population d. the variance of the sample

the variance of the population

10. The 75th percentile is referred to as the a. first quartile b. second quartile c. third quartile d. fourth quartile

third quartile

14. Which of the following is not a measure of central location? a. mean b. median c. variance d. mode

variance

37. Which of the following symbols represents the mean of the population? a. σ2 b. σ c. μ d. -x

μ

36. Which of the following symbols represents the standard deviation of the population? a. σ2 b. σ c. μ d. -x

σ

38. Which of the following symbols represents the variance of the population? a. σ2 b. σ c. μ d. -x

σ2