Of the 13,500 savings accounts in a bank, 4,675 belong to people
younger than 40 years old. The bank president would like to
increase her institution's marketing strategy to younger customers,
so she is examining the population proportions in order to create a
statistical study. Find the population proportion, as well as the
mean and standard deviation of the sampling distribution for
samples of size n=400 . Round all answers to 3 decimal places.