Question

A consumer organization inspecting new cars found that many had appearance defects. While none had more than 3 defects, 7% had three, 11% had two, and 21% had one defect. Find the expected number of appearance defects in a new car, and the standard deviation.

Answer 1

Answer:

E(X) = 0.64

Sd(X) = 0.933

Step-by-step explanation:

3(0.07) + 2(0.11) + 1(0.21)

E(X²) = 3²(0.07) + 2²(0.11) + 1²(0.21)

= 1.28

Var(X) = 1.28 - 0.64² = 0.8704

Sd = 0.933