Question

The arithmetic mean if ui = xi - 25 / 10 sigma fiui = 20 and sigma fi = 100 is

Answer 1

27

Explanation:

Given the formula ui = xi - 25 / 10

Note that the general formula for calculating ui = xi-A/n where;

A = assumed mean

n = class size

On comparison with the given equation, A = 25 and h = 10

Also arithmetic mean x = A + {h * sigma(fiui) /sigma(fi)} where;

sigma(fiui) = 20 and sigma fi = 100

Substituting the given value to get the mean x;

x = 25+ (10*20/100)

x = 25 + (200/100)

x = 25 + 2

x = 27

The arithmetic mean is 27