Question

18. The servicing of a machine requires two separate steps, with the time needed for the

Answer 1

Answer:

Step-by-step explanation:

Let X denote the first step

Let Y denote the second step

Then

E(X) = 0.2

E (Y) = 0.3

V (X) = 0.04

V (Y) = 0.09

Now,

E(X,Y) = E[X] + E{Y}

0.2 + 0.3 = 0.5

And since X and Y are independent

Therefore,

V(X , Y) = V(X) + V(Y)

= 0.04 + 0.09

= 0.13

Now required probability is

$P\{ \sum X_i+\sum Y_i$

= Φ(-1.24)

= 1 - Φ (1.24)

= 1 - 0.8925

= 0.1075