FREE MODULE Introduction to Statistics

Introduction to Statistics Exercises

The scores of a group of students in a course on statistics are: 62 52 67 78 47 55 57 44 58 48 77 82 43 63 59 61 66 61 76 54 spreadsheet a. Find the mean of the scores b. Find the median of the scores c. Calculate the standard deviation of the scores d. Draw a histogram of the scores The weights of a group of men (in kilograms) were recorded as follows: 82 79 80 80 72 74 88 82 112 83 77 86 81 84 78 72 87 70 78 97 spreadsheet a. Calculate the standard deviation of the weights b. Draw a histogram of the weights The following times (in minutes) to process hot-rolled steel were observed for a random sample of size 10: 5.4 6.2 7.9 4.8 7.5 6.2 5.5 4.5 7.2 6.2 spreadsheet a. Estimate the variance of the processing times Two systems for measuring the calcium content of laboratory samples were being considered. A standard sample, containing 100 units of calcium was weighed 16 times using each system. The results were: System 'A' 105 102 102 105 106 107 108 108 104 105 107 104 103 105 107 105 System 'B' 95 95 99 102 97 107 98 103 101 103 109 100 100 91 98 96 spreadsheet Which system is potentially the 'best'? System A: System B:

The scores of a group of students in a course on statistics are:

62

52

67

78

47

55

57

44

58

48

77

82

43

63

59

61

66

76

54

spreadsheet

The weights of a group of men (in kilograms) were recorded as follows:

79

80

72

74

88

112

83

86

81

84

87

70

97

The following times (in minutes) to process hot-rolled steel were observed for a random sample of size 10:

5.4

6.2

7.9

4.8

7.5

5.5

4.5

7.2

Two systems for measuring the calcium content of laboratory samples were being considered. A standard sample, containing 100 units of calcium was weighed 16 times using each system. The results were: System 'A' 105 102 102 105 106 107 108 108 104 105 107 104 103 105 107 105 System 'B' 95 95 99 102 97 107 98 103 101 103 109 100 100 91 98 96 spreadsheet

Two systems for measuring the calcium content of laboratory samples were being considered. A standard sample, containing 100 units of calcium was weighed 16 times using each system. The results were:

System 'A'

System 'B'