The normal approximation is appropriate when np and n(1-p) are both large. How large depends on what textbook/lecturer you have. If you are feeling keen, calculate both the exact value and the approximation and compare them.a. Can you use the normal approximation to the binomial distribution to estimate
the probability that between 22 and 35 of them have faulty control panels?
If np and n(1-p) are large, ,b. Estimate the probability that between 22 and 35 of them (including 22 and 35)
have faulty control panels.
Where Y has distribution N(np, np(1-p))