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

27

Step-by-step 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