Question

A machine produces microchips. A produced microchip is faulty with a probability of p = 0.14 . What is the probability that in a random sample of 4 microchips, 2 are faulty and 2 are ok?

Answer 1

`\begin{gathered} =4C_2(0.14)^2(0.86)^2 \\ =(4!)/(2!2!)*0.0916*0.7396 \\ =(4*3*2)/(2*2)*0.0677 \\ =6*0.0677 \\ =0.4064 \end{gathered}`