In: Statistics and Probability
This question is all together so all steps must be answered please!
Members of a labor union were asked their ages. The frequency distribution for this sample is given below. Ages, in years
Class limits frequency
15 – 24 60
25 – 34 195
35 – 44 283
45 – 54 140
55 – 64 42
65 - 74 10
[10] (6 pts) Find the mean (show work)
[11] (3 pts) Identify the modal class
[12] (6 pts) Calculate the variance (show work)
[13] (3 pts) Calculate the standard deviation
Solution :
Class limits frequency midpoint
f x
15 – 24 60 19.5
25 – 34 195 29.5
35 – 44 283 39.5
45 – 54 140 49.5
55 – 64 42 59.5
65 - 74 10 69.5
[10] => mean = 38.6640
[11] => Modal class is 35 - 44
The modal class is the group with the highest frequency.in this group 35 - 44 jas the highest frequency that is 283
[12] => variance = 113.5670
[13] => standard deviation = 10.6570