Answer:
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
