Answer:
The expected value for the random variable is 14.16.
Step-by-step explanation:
We are given the following data below;
Z P(Z) [tex]Z \times P(Z)[/tex]
9 0.16 1.44
12 0.25 3
15 0.36 5.4
18 0.17 3.06
21 0.06 1.26
Total 1 14.16
Now, the expected value for the random variable Z is given by;
E(Z) = [tex]\sum Z \times P(Z)[/tex]
= [tex](9 \times 0.16) + (12 \times 0.25) +......+(21 \times 0.06)[/tex]
= 14.16.