Question

If n = 100, x = 3 and S² = 11 then [(∑xi²)/(∑xi)] is ______ 

(a) 10

(b) 22 

(c) 6.66

(d) 2000

Answer 1

The correct option (c) 6.66   

Explanation:

∑xi = n ∙ x = 100 × 3 = 300

∑(xi)² = n(S² + x²) = 100(11 + 9) = 2000 

∴ [(∑xi²)/(∑xi)] = [(2000)/(300)] = (20/3) = 6.66.