Question

If the mean of the following data is 15, find p.

x:	5	10	15	20	25
f:	6	p	6	10	5

Answer 1

\(Mean =\frac{ \sum fx}{N}\)

= \(\frac{(10p\, +\, 445)}{(p\, +\, 27)}\) 

Mean = 15

So, \(\frac{(10p\, +\, 445)}{(p\, +\, 27)}\) = 15 

10p + 445 = 15(p + 27) 

10p – 15p = 405 – 445 = -40 

-5p = -40 

or p = 8

⇒ The value of p is 8.