Question

Find the sum and the sum of the square of

100 items whose mean is 50, and S.D. is 5.​

Answer 1

Answer:

Correct option is

A

5000,251600

Here n=100,A=50,σ=4

Now, A=n∑x⇒∑x=nA=100×50=5,000

Again, from the formula,

σ2+A2=n∑x2⇒∑x2=n(σ2+A2)

∴∑x2=n(σ2+A2)=100(16+2500)=251600