Thread: Elem Stats question

Data: 67, 10, 53, 32, 62, 55, 29, 38, 58, 48, 73, 63, 62, 34, 47, 29, 43, 42, 38, 72, 51, 36, 35, 62, 93.

R = 83
CW = 17

Question: If the lower class limit in X of the first class were 15, what would the upper class boundary be? (Assume the number of classes is 5)
Answer 31.5

Question: Class boundaries of the third class, assuming the lower class limit of the first class is 15 and the number of classes is 5.
Answer 48.5 - 65.5

Question: What is the cumulative relative frequency in X of the third class? (Assuming LCL is 15 and # of classes is 5)
Prof answer .80 =40/50 = 20/25 My answer .86 = 20/24

My question - If you start with 15 as the lower class limit, what happens to the 10? I am sure there is an easy answer but I do not know and the text has not spelled it out for me yet.

Truly would appreciate I clear answer so I can continue with Relative frequency, the class mark, sample standard deviation, z-score for 62 in X, etc....

Thanks!