Question

The heights, x cm, of the 10 girls in an athletics team are such that 

sum of x (∈x) =1550 and ∈x∧2= 241250

a- find the mean and variance
b- one girl, who is 173cm tall, drops out of the tem. calculate the mean and variance of the heights of the remaining nine members of the team

Answer 1

use the standard deviation equation attached to work this one out. They have given you totalX^2 and sum of X and n, just substitute and work through.