Chapter 15: Statistics

Q1. Find the mean of: 4, 7, 8, 11, 12, 16, 20.

Solution

Mean = (4+7+8+11+12+16+20)/7 = 78/7 = 11.14

Q2. Find the variance of: 2, 4, 6, 8, 10.

Solution

Mean = 6
Variance = [(2-6)²+(4-6)²+(6-6)²+(8-6)²+(10-6)²]/5
= [16+4+0+4+16]/5 = 40/5 = 8