Question

Make a frequency table using five classes.

class 31-38 39-46 47-54 55-62 63-70
f
11
24
15
7
3

Then estimate the mean and sample standard deviation using the frequency table. (Round s to two decimal places.)

Answer 1

Answer: C

Explanation:

Answer 2

The mean of the given data would be given below as follows:

mean = 199.10

How to calculate the mean of data with frequency table?

To calculate the mean of the given data, the mid point or the ranges given are first determined. That is;

31-38 = 31+38/2 = 69/2 = 34.5

39-46 = 39+46 = 85/2 = 42.5

47-54 = 47+54 = 101/2 = 50.5

55-62= 55+62/2 = 117/2 = 58.5

63-70 = 63+70/2 = 133/2 = 66.5

But mean = Total/number of data

Total = 11×34.5+24×42.5+15×50.5+7×58.5+3×66.5

= 379.5+10200+757.5+409.5+199.5

= 11,946

Number of data = 11+24+15+7+3= 60

The mean of data = 11946/60=199.1