Question

The ages (in years) of a random sample of shoppers at a gaming store are given below: 12 19 23 14 20 16 21 18 14 19 What is the variance

Answer 1

Answer: the required variance is 11.6555

Explanation:

Given data;

xi = 2 19 23 14 20 16 21 18 14 19

mean x" = 2+19+23+14+20+16+21+18+14+19 / 10

mean x" = 166 / 10 = 16.6

so;

X xi - x" (xi - x")²

12 -4.9 24.01

16 -0.9 0.81

23 6.1 37.21

13 -3.9 15.21

18 1.1 1.21

18 1.1 1.21

19 2.1 4.41

18 1.1 1.21

13 -3.9 15.21

19 2.1 4.41

Total 104.9

Variance = n_i=1∑(xi - x")² / n-1

Variance = 104.9 / 9

Variance = 11.6555

Therefore, the required variance is 11.6555