1. Calculate the mean and standard deviation of the following distribution:
Age (Years): 25-30 30-35 35-40 40-35 45-50 5O-55
No of workers: 70 51 47 31 29 22
2. (a) Your are supplied the following data about height of boys and girls in a college:
|
Boys
|
Number
72
|
Average He/gl,t
68"
|
Variance
9"
|
|
Girls
|
38
|
61"
|
4"
|
You are required to find out (i) the combined mean and S.D. of heights of boys and girls taken together, and show (ii) whose height is more variable?
(b) Find mean deviation and its coefficient of the following series:
|
Size
|
1O
|
1 1
|
12
|
13
|
14
|
|
Frequency :
|
5
|
12
|
18
|
12
|
3
|