Question

Find the mean of the discrete random variable with the probability distribution below.

x 5 9 12 14 19
P(x) 0.2 0.15 0.1 0.3 0.25

Answer 1

have you been introduced to 'weighted averages'

Answer 2

if so I can help, if not i can still help, but the method might not be what your professor wants you to do

Answer 3

E[X] = 5(.2) + 9(.15) + 12(.1) + 14(.3) + 19(.25) = 12.5

Answer 4

nicely done!, but you are missing one part..
\[\frac{ 5(.2) + 9(.15) + 12(.1) + 14(.3) + 19(.25) }{ .2 + .15 + .1 + .3 + .25}\]

Answer 5

make sense?