Question

Find the value of P for the following distribution whose mean is 10

$x_1$	5	7	9	11	13	15	20
$f_i$	4	4	p	7	3	2	1

Answer 1

$x_i{f}_i=20,28,9p,77,39,30,20$

Mean$=\frac{\sum x_i{f}_i}{\sum f_i}=\frac{214+9p}{p+21}=10$

$\Rightarrow 9p+214=10p+210$

$\Rightarrow p=4$.