Surely you can do the first part. It's a straightforward application of the normal distribution.
For the second part you just need to know what the mean and standard deviation of the random samples are.
Given N samples you should know that the sample mean is distributed as \(\displaystyle Normal\left(\mu, \dfrac{\sigma_p}{\sqrt{N}}\right)\)
where \(\displaystyle \mu=14~yr\) is the population mean and \(\displaystyle \sigma_p=7.5~yr\) is the standard deviation of the population.
Then just apply what you did in the first part of the problem with the new standard deviation.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
