Psychology and Statistics

Psychologyand Statistics

Answersto Chapter Seven Review Exercise

1.Frequency distribution table 2. Qualitative variable

3.Histogram 4 .Central tendency

5.Median 6. Standard deviation

7.Sample mean 8. Population, sample

9.Standard score 10. Standard normal distribution.

11.Pearson 12. Point-biserial

13.Coefficient of determination 14. Regression analysis

Multiple-ChoiceSelf-Test

1.C 2. C 3. D 4. B 5. B 6. B 7. D 8. A 9. A 10. B

11.B 12. A 13. A 14. A 15. A 16. A 17. C 18. A

1.Frequency Distribution Table.

Speed

Frequency

Relative Frequency

62

1

0.05

64

3

0.15

65

4

0.2

67

3

0.15

68

2

0.1

70

2

0.1

72

1

0.05

73

1

0.05

76

1

0.05

79

1

0.05

80

1

0.05

2.Class Interval Frequency.

Class interval

Frequency

Relative frequency

50-54

0

0

55-59

0

0

60-64

4

0.2

65-69

9

0.45

70-74

4

0.2

75-79

2

0.1

80-84

1

0.05

85-89

0

0

90-94

0

0

95-99

0

0

3. A histogram is suitable because it graphically represents thenumerical data distribution

4. Mean = 68.35

Median=67

Mode= 65

Thedistribution is skewed because there is no frequency above of morethan one on the speed above 70.

5.(a) Mean= 7.3

Median=8.5

Mode= 11

(b) Mean= 4.83

Median=5

Mode=5

(c) Mean= 6.1667

Median=6.5

Mode=3 and 8

(d) Mean = 5.5

Median=6

Mode=6

6.(a) Range =8

Standarddeviation =2.2

(b) Range= 8

Standarddeviation = 2.2

(c) Range= 80

Standarddeviation= 22

(d) Range =0.8

Standarddeviation = 0.22

(e) Range =800

Standarddeviation = 220

Reference

Garrett,H. E. (1966).&nbspStatisticsin psychology and education.New York: McKay