The time X to failure of a machine has pdf f (x) = (x/4)3e −(x/4)4, 0 < x < ∞. Compute P(X > 5 |X > 4).

Step 1 of 2:

Given that X denotes the time to failure of a machine. X has the probability density

f(x)=,0<x<.

We have to find the value of P(X>5|X>4).