statistics
posted by ALFREDA on .
I need to find the class midpoint, boundaries and class with for the following problem
Tar Cigarette Filter Frequency
25 2
69 2
1013 6
1417 15
I did the midpoint and boundaries
3.5 5.5
7.5 9.5
11.5 13.5
15.5 17.5
But for the width I got an answer of 1.25 can someone please let me know if I have the problem correct.

Example:
Class limit is 11  20
Class midpoint is (11 + 20)/2 = 15.5
Class boundary is 10.5  20.5 (.5 below and .5 above)
Class width is 20.5  10.5 = 10
I hope this example will help. 
No it didn't I just wanted to know if I was correct that's all thanks for nothing mathguru

The example was meant to show you how to do the problem without doing it for you.
You are correct on the midpoints.
You are missing the lower class boundaries.
You are missing the class widths for each class.