Question

find the value for p, if the mean of the following distribution is 18​

Answer 1

Answer:

p = 1.

Step-by-step explanation:

Mean = ∑xf / ∑f

= (13*8 + 15*2 + 17*3 + 19*4 + (20 + p)5p + 23*6) / (8+2+3+4+5p+6)

= (5p^2 + 100p + 399) / (5p + 23) = 18

5p^2 + 100p + 399 =  18(5p + 23)

5p^2 + 100p + 399 =  90p + 414

5p^2 + 10p - 15 =  0

p^2 + 2p - 3 = 0

(p + 3)(p - 1) = 0

p = 1 ( as p cannot be negative - we cannot have a frequency of 5*-3)