In a lot of 10 microcircuits, 3 are defective. Four microcircuits are chosen at random to be tested. Let X denote the number of tested circuits that are defective.

a. Find P(X = 2).

b. Find μX

c. Find σX

Answer:

Step 1 of 4:

Given, we have a lot of 10 microcircuits, in that 3 are defectives and 4 microcircuits are chosen at random to be tested.

Let X = number of tested circuits that are defectives.

Let X follows Hypergeometric distribution with probability mass function is

P(x) =

X~H(10, 3, 4).

From the given problem, N = 10, K = 3 and n = 4