Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and...

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Standard Deviation and Variance (Class 2) OBJ: • Find range, measures of central tendency, and construct tables and graphs

Transcript of Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and...

Page 1: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Standard Deviation and Variance (Class 2)

OBJ: • Find range, measures of central tendency, and construct

tables and graphs

Page 2: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Below are the algebra test scores for a class of 25 students:

56 57 58 60 61 65 67 68 70 71 74 75 77

79 82 87 88 89 92 95 96 97 98 99 99

Page 3: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Calculator commands: (at thebottom of the second page of notes)

• STAT, 1 (for EDIT), 50,ENTER (repeat for all data), STAT, (for CALC), 1 (for 1-VAR STAT), ENTER (To clear data,▲L1, CLEAR, ENTER)

• 2ND STAT (for LIST), (for MATH), 8, (for VARIANCE), 2ND 1 (for L1)

Page 4: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Give the mean, median, and mode

Mean

78.4

Median

77

Mode

99

Page 5: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Give the standard deviation and variance

Standard deviation

14.8

Variance

218.1

Page 6: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Below are the algebra test scores for a class of 25 students:

50 64 68 70 70 72 73 75 75 76 78 78 79

80 81 82 82 82 85 88 88 89 90 92 93

Page 7: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Below are the algebra test scores for a class of 25 students:

56 57 58 60 61 65 67 68 70 71 74 75 77

79 82 87 88 89 92 95 96 97 98 99 99

Page 8: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Give the mean, median, and mode. Give the standard deviation and variance

Class 1 Class 2

Mean

78.4

Median

79

Mode

82

Standard deviation

9.8

Variance

95.2

Mean

78.4

Median

77

Mode

99

Standard deviation

14.8

Variance

218.1

Page 9: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Give range and class width

Range

99-56

43

Class Width

43

6

7 1/6 →

8

Page 10: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a frequency table and a cumulative frequency table with 6 classes

56

57

58

60

61

65

67

68

70

71

74

75

77

79

82

87

88

89

92

95

96

97

98

99

99

Class

Relative

Frequency

Page 11: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a frequency table and a cumulative frequency table with 6 classes

Class

Relative

Frequency Class

Relative

Frequency

56-63 5

64-71 5

72-79 4

80-87 2

88-95 4

96-103 5

Page 12: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a frequency table and a cumulative frequency table with 6 classes

Class

Relative

Frequency

56-63 5

64-71 5

72-79 4

80-87 2

88-95 4

96-103 5

Cumulative Frequency

Class

< 56

# %

0 0

Page 13: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a frequency table and a cumulative frequency table with 6 classes

Class

Relative

Frequency

56-63 5

64-71 5

72-79 4

80-87 2

88-95 4

96-103 5

Cumulative

ClassFrequency

# %

< 56 0 0 %

< 64 5 20 %

< 72 10 40 %

<80 14 56 %

< 88 16 64 %

< 96 20 80 %

< 104 25 100%

Page 14: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a histogram. Clearly mark axes.

F

r

e

q

u

e

n

c

y

Test Scores

Class Relative

Frequency

56-63 5

64-71 5

72-79 4

80-87 2

88-95 4

96-103 5

25

Page 15: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Go to frequency polygon at the top of the next page of notes.

Give all class marks.

56 + 63

2

59.5

64 + 71

2

67.5

59.5

67.5

75.5

83.5

91.5

99.5

Page 16: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct a frequency polygon, mark axes

Frequency

Test Scores

Class

Mark 51.5

Relative

Frequency

59.5 5

67.5 5

75.5 4

83.5 2

91.5 4

99.5 5

107.5 25

Page 17: Standard Deviation and Variance (Class 2) OBJ: Find range, measures of central tendency, and construct tables and graphs.

Construct an ogive. Clearly mark both axes

R C F e u r l m ea u qt l ui a ev t ne i c v y e

Test Scores

Cumulative

ClassFrequency

# %

< 56 0 0 %

< 64 5 20 %

< 72 10 40 %

<80 14 56 %

< 88 16 64 %

< 96 20 80 %

< 104 25 100%