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

The administrator of a large assisted living facility wanted to know the average age of the residents living at the facility. he randomly selected 12 residents and determined their age, listed here: 80, 65, 75, 83, 68, 73, 88, 79, 94, 72, 79, 68 what's the average age of the sample of residents? a. 79 years old b. 68 years old c. 75 years old d. 77 years old

Ineed to know the answer to this algebra question.

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76