# MATHEMATICS

In a bell-shaped distribution, ____.

1. median = mean
2. median < mean
3. median > mean
4. standard deviation equals variance

34. (Points: 1)

The most commonly encountered measure of variability is ____.

1. range
2. mean
3. mode
4. standard deviation

35. (Points: 1)

The mean is ____ sensitive to extreme scores than the median.

1. equally
2. less
3. can’t say without the scores
4. more

36. (Points: 1)

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

Refer to Exhibit 5-1. The percentile rank of a price of \$13.87 is ____.

1. 51.22%
2. 98.78%
3. 1.22%
4. 48.78%

37. (Points: 1)

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

Refer to Exhibit 5-1. What percentage of the distribution lies between \$5 and \$11?

1. 49.41%
2. 21.48%
3. 57.98%
4. 78.41%

38. (Points: 1)

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

Refer to Exhibit 5-1. What percentage of the distribution lies below \$7.42.

1. 31.92%
2. 32.28%
3. 17.72%
4. 82.28%

39. (Points: 1)

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

Refer to Exhibit 5-1. The stock price beyond which 0.05 of the distribution falls is ____.

1. \$ 4.60
2. \$12.47
3. \$12.44
4. \$ 4.57

40. (Points: 1)

Exhibit 5-1

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of \$8.52 with a standard deviation of \$2.38.

Refer to Exhibit 5-1. The percentage of scores that lie between \$9.00 and \$10.00 is ____.

1. 23.24%
2. 15.31%
3. 7.93%
4. 31.17%

41. (Points: 1)

The standard deviation of the z distribution equals ____.

1. 0
2. S X
3. N
4. 1

42. (Points: 1)

The mean of the z distribution equals ____.

1. S X
2. N
3. 0
4. 1

43. (Points: 1)

In a normal distribution approximately ____ of the scores will fall within 1 standard deviation of the mean.

1. 95%
2. 83%
3. 14%
4. 70%

44. (Points: 1)

If a distribution of raw scores is negatively skewed, transforming the raw scores into z scores will result in a ____ distribution.

1. positively skewed
2. bell-shaped
3. normal
4. negatively skewed

45. (Points: 1)

In the equation, Y = bX + a, a is ____.

1. a variable relating Y to X
2. a constant giving the value of the Y axis intercept
3. a constant giving the value of the slope of the line
4. a variable relating X to Y

46. (Points: 1)

In a perfect relationship, ____.

1. all the points fall on the line
2. some of the points fall on the line
3. the points form an ellipse around the line
4. none of the points fall on the line

47. (Points: 1)

The lowest degree of correlation shown below is ____.

1. -0.25
2. -0.33
3. 0.15
4. 0.75

48. (Points: 1)

Rho is used ____.

1. when both variables are dichotomous
2. when one or both variables are only of ordinal scaling
3. when the data is nonlinear
4. when both variables are of interval or ratio scaling

49. (Points: 1)

Exhibit 6-1

A traffic safety officer conducted an experiment to determine whether there is a correlation between people’s ages and driving speeds. Six individuals were randomly sampled and the following data were collected.

Age
20
25
45
46
60
65
Speed (mph)
60
47
55
38
45
35

Refer to Exhibit 6-1. The value of Pearson r equals ____.

1. +0.70
2. -0.70
3. -0.82
4. -0.63

50. (Points: 1)

Exhibit 6-1

A traffic safety officer conducted an experiment to determine whether there is a correlation between people’s ages and driving speeds. Six individuals were randomly sampled and the following data were collected.

Age
20
25
45
46
60
65
Speed (mph)
60
47
55
38
45
35

Refer to Exhibit 6-1. The proportion of variability of Y accounted for by X is ____.

1. -0.49
2. 0.67
3. 0.40
4. 0.49

51. (Points: 1)

The primary reason we use a scatter plot in linear regression is ____.

1. to determine the slope of the least squares regression line
2. to determine if the relationship is linear or curvilinear
3. to compute the magnitude of the relationship
4. to determine the direction of the relationship

52. (Points: 1)

For the following points what would you predict to be the value of Y’ when X = 19? Assume a linear relationship.

X
6
12
30
40
Y
10
14
20
27

1. 17.75
2. 16.35
3. 24.69
4. 22.00