Let x1,x2,...,xn be n observaions such that ∑xi 2 = 400 and ∑xi = 80, then a possible value of n is
a. 9
b. 12
c. 15
d. 18
Please explain briefly
Let x1,x2,...,xn be n observaions such that ∑xi 2 = 400 and ∑xi = 80, then a possible value of n is
a. 9
b. 12
c. 15
d. 18
Please explain briefly