Data Set 1: Math Pretest Scores

(Calculating Mean, Variance, and Standard Deviation)

Test Scores Step 1  Step 2

Difference Square 

100

98

96

94

88

87

82

80

76

75

75

75

73

72

71

70

68

67

59

54

Sum =

MEAN = Step 3 Sum of Squares =

Step 4: Divide sum of squares by N 

Variance =

Step 5: Standard deviation = square root of Step 4.

STANDARD DEVIATION =

Data Set 2: Math Pretest Scores

(Calculating Mean, Variance, and Standard Deviation)

Test Scores Step 1 Step 2

Difference Square 

98

98

89

86

78

76

76

75

75

75

75

74

74

73

72

68

65

59

58

56

Sum =

MEAN = Step 3 Sum of Squares:

Step 4 Divide sum of squares by N = 

Variance =

Step 5: Standard deviation = square root of Step 4.

STANDARD DEVIATION =