Use the Normal curve approximation to the binomial distribution. Two percent of hair dryers produced in a certain plant are defective. Estimate the probability that of 10,000 randomly selected hair dryers, at least 219 are defective.
Here, n = 10,000 and p = 2% = 0.02.
Therefore, np= 10000(0.02) = 200 and n(1-p) = 10000(0.98) = 9800.
Since both np and n(1-p) are greater than 5, we may use normal approximation to the Binomial distribution.
The mean and standard deviation ...
The solution describes the method of the normal curve approximation to the binomial distribution.