Descriptive Statistics & Frequency Distributions

Use the test score demonstration data we used in class. A copy of the basic frequency distribution is available on the next page.

1. Create a new SPSS data file. Define the necessary variables. Think of each score as belonging to a single participant and assign an ID # for each participant (this should be your first variable).

2. Input the data.

3. Using the Frequencies command within the Descriptive Statistics menu (Analyze),

find the following information:

Minimum Score ____________________

Maximum Score ____________________

Mean ____________________

Median ____________________

Mode ____________________

Variance ____________________

Standard Deviation ____________________

25^th Percentile ____________________

50^th Percentile ____________________

75^th Percentile ____________________

Skewness ____________________

What does this measure of Skewness tell you?

What cumulative proportion of scores fall at or below a test score of 84?

What cumulative proportion of scores fall at or below a test score of 67?

CLASS EXAMPLE

FREQUENCY DISTRIBUTION

Test Score Frequency N = 50

100 1

99 1

96 1

95 1

93 3

92 2

91 1

90 2

89 1

88 1

87 1

86 2

85 1

84 2

83 3

82 1

81 3

80 2

78 2

77 2

76 2

75 1

74 2

73 1

72 1

67 1

66 1

65 1

64 1

63 1

62 1

61 1

60 1

59 1

57 1

50