Find the missing value of p, for the following distribution whose mean is 12.58.
x: | 5 | 8 | 10 | 12 | p | 20 | 25 |
f : | 2 | 5 | 8 | 22 | 7 | 4 | 2 |
X | f | fx |
5 | 2 | 10 |
8 | 5 | 40 |
10 | 8 | 80 |
12 | 22 | 264 |
p | 7 | 7p |
20 | 4 | 80 |
25 | 2 | 50 |
N = 50 | ∑fx = 7p + 524 |
Given, mean = 12.58
= 12.58
= 12.58
7p = 629 – 524
7p = 105
p =
= 15