21. The mean serves as the single most preferred average for

a. all data

b. any frequency distribution

c. Quantitative data

d. Ungrouped data

22. Averages are sometimes referred to as measures of central tendency. This description is somewhat misleading particularly when

a. The mean is used with a highly skewed distribution

b. The median is used with a highly skewed distribution

c. The mode is used with a highly skewed distribution

d. None of the above

23. If qualitative data can be ordered, It's possible to use

a. Any average

b. The mean or mode

c. The mean or median

d. The mode or median

24. It would be appropriate to report the median for a distribution of

a. Political preferences

b. Countries of birth

c. Academic majors

d. None of the above

25. For the following observations: 2, 5, 3, 2, 4, 6, 2, 4, the mode equals

a. 2

b. 3

c. 4

d. none of the above

26. In its role as a balance point, the mean balances

a. The distance of the largest observation against the distance of the smallest observation

b. The combined distance of all observations above the mean against the combined distance of all observations below the mean

c. The number of larger observations against the number of smaller observations

d. all of the above

27. When a distribution is skewed, report

a. The median

b. Both the median and mode

c. Both the median and mean

d. The mean

28. Which average - the mode, the median, or mean -- probably serves as the basis for the following statement? The average wage earner's income is substantially higher than the lowest 50 percent of wage earners.

a. Mode

b. Median

c. Mean

d. Impossible to determine on the basis of available information

29. The distribution of annual incomes for U.S. households is positively skewed. If the Census Bureau reports a median annual income of $57, 450, this implies that the mean annual income is

a. About the same

b. Larger

c. Smaller

d. Either larger or smaller, but it's impossible to decide on the basis of the available information

30. The mode reflects the value

a. Of the largest frequency

b. Of the most frequently occurring observation

c. Midway between the largest and smallest observations

d. Of the largest observation

41. The intuitive approach to searching for a relationship becomes cumbersome and inexact when

a. There are more than a few pairs of observations

b. Little or no relationship is present

c. The relationship is negative

d. Observation assume values with decimal points

42. Without, doing any calculations describe the relationship for the following pairs of observations

X Y

6 118

12 109

3 144

10 111

1 142

a. Positive

b. Negative

c. Little or no relationship

d. Impossible to describe

43. For a strong (but imperfect) negative relationship, a z score of 2.34 will be paired with a z score

a. In the vicinity of -2.34

b. In the vicinity of 2.34

c. Of 2.34

d. Of 2.34

44. Although designed originally for use with quantitative data, the Pearson r has been extended to other kinds of situations, including those that involve

a. Ranks

b. Ordered qualitative data

c. Ordered qualitative and quantitative data

d. All of the above

45. Which one of the following most likely describes a positive relationship?

a. Automobile weight and gas mileage

b. Test score and time to complete test

c. Current age and remaining years of life expectancy

d. Years of education and lifetime earnings

36. It's most correct to view the normal curve as

a. A batch of observations

b. A frequency distribution

c. An observed frequency distribution

d. A theoretical frequency distribution

37. A negative z score signifies that the original score is

a. Negative

b. Below the mean

c. Considerably below than the mean

d. Some small number

38. Proportions of area under the normal curve are

a. Either positive or negative

b. Always negative

c. Always positive

d. None of the above

39. A test score located two standard deviations above the mean could be reported as a z score of 2.00. Or in a distribution of T scores with a mean of 50 and a standard deviation of 10, it could be reported as a T score of

a. 50

b. 52

c. 60

d. 70

40. Since the normal curve never actually touches the horizontal axis

a. Most of the area is in its extremities

b. The total area is infinitely large

c. The normal tables are only approximate

d. Very extreme observations are possible

31. Among frequency distributions for physical stamina scores, the greatest variability probably would occur in the distribution for

a. Well trained athletes

b. Patients at a health clinic

c. Infants

d. The general population

32. If the distribution of weekly study times reported by college students has a mean of 25 hours with a standard deviation of 10 hours, this implies that

a. A small minority study either less than 5 hours or more than 45 hours

b. A majority study between 15 and 35 hours

c. Individuals deviate, on the average, approximately 10 hours from the mean of 25 hours

d. All of the above

33. The standard deviation never can be

a. Zero

b. Smaller than the mean

c. Negative

d. Larger than the mean absolute deviation

34. If qualitative data can be ordered (ordinal measurement), it's appropriate to describe variability by

a. Calculating the standard deviation

b. Determining the distance between extreme observations

c. Identifying extreme observations

d. Approximating the mean deviation

35. When calculating the variance and standard deviation, you always must find the value of the

a. Mean

b. Mean deviation

c. Sum of the deviations

d. Sum of squares

Bonus Question:

Using the Sample Computation Formula, Find the Standard Deviation for the distribution 23, 19, 19, 26, 9, 30, 3, 3, 7, 9, 1, 6. Show all work