Answer :
Answer:
b. 9.2 minutes
Step-by-step explanation:
To find the expected waiting time for a random call from the sampie given by using the formula:
[tex]\sum (f(X)) = \dfrac{\sum f (x) \times x}{\sum x}[/tex]
number of calls (x) waiting time f(x) in minutes f(x) *(x)
0 0 0
2 3 6
4 10 40
6 15 90
8 10 80
10 6 60
[tex]\sum x = 30[/tex] [tex]\sum f(x) *x = 276[/tex]
Therefore:
[tex]\sum (f(X)) = \dfrac{276}{30}[/tex]
[tex]\sum (f(X)) = 9.2[/tex]