Lifetime of electronics: In a simple random sample of 100 electronic components produced by a certain method, the mean lifetime was 125 hours. Assume
that component lifetimes are normally distributed with population standard deviation a 20 hours. Round the critical value to no less than three decimal
places.

(b) Find the sample size needed so that a 99.8% confidence interval will have a margin of error of 4.
A sample size of is needed so that a 99.8% confidence interval will have a margin of error of 4. Round the sample size
up to the nearest integer.