According to a recent survey, the average earnings in a certain city were $42,000 in Educational Services and $75,400 in the Financial Services industry. a) Suppose the standard deviation of earnings in Educational Services for the whole of the city was $14,900 and we want the standard deviation of average earnings in our survey to be $1100. What sample size do we need to take? b) Suppose we used a sample of size 480 for our estimate of average earnings in Financial Services and the standard deviation of earnings in our survey was $17,200. What is the standard error of the average earnings in Financial Services? a) The sample size needed is (Round up to the nearest whole number.)