In Exercises 5–10, identify the class width, class midpoints, and class boundaries for the given frequency distribution. The frequency distributions are based on real data from Appendix B.
Solution 7BSC
87652.27BSC AID: 520  10/08/2013
RID: 558  11/09/2013
RID1: 17922  12/02/2016
We know that, the numbers used to separate the classes in a frequency distribution known as class boundaries so that the continuity in the classes without the gaps created by class limits.
The value in the middle of the class known as Class midpoint and is computed by summing the lower and upper class limits and dividing the result by 2.
The difference between two consecutive upper class limits in a frequency distribution known as the class width.
For the first class, the midpoint of that class is and the class width of that class is.
Similarly, for other classes calculated and given in the following table:
Verbal IQ Score of Subject Exposed to Lead 
Frequency 
Lower Class Limits 
Upper Class Limi1ts 
Class Boundaries 
Class Mid Points 
Class Width 

Lower 
Upper 

5059 
4 
50 
59 
49.5 
59.5 
54.5 
10 
6069 
10 
60 
69 
59.5 
69.5 
64.5 
10 
7079 
25 
70 
79 
69.5 
79.5 
74.5 
10 
8089 
43 
80 
89 
79.5 
89.5 
84.5 
10 
9099 
26 
90 
99 
89.5 
99.5 
94.5 
10 
100109 
8 
100 
109 
99.5 
109.5 
104.5 
10 
110119 
3 
110 
119 