Listed in increasing order are the same creatine phosphokinase (CK) levels of (U/I) of 36 healthy men (these are the data given below):
25 62 82 95 110 139
42 64 83 95 113 145
48 67 84 100 118 151
57 68 92 101 119 163
58 70 93 104 121 201
60 78 94 110 123 203
The sample mean CK level is 98.3 U/I and the SD is 40.4 U/
What percentage of the observations are within:
(a) 1 SD of the mean?
(b) 2 SDs of the mean?
(c) 3 SDs of the mean?
(d) Compare the results with the predictions of the empirical rule.