Question

In a network of 40 computers, 5 hold a copy of a particular file. Suppose that 7 computers at random fail. Let F denote the number of computers that fail and have a copy of the file. What is E[F]

Answer 1

0.875

Explanation:

Here we are tasked with calculating E[F]

The probability of success here is given by;

P = 5/40 = 1/8 or 0.125

Now according to the question, our sample size is 7 i.e n = 7

Mathematically, expected value E(x) is given as np

= 7 * 0.125 = 0.875

Thus E[F] = 0.875