A stratified simple random sample is to be taken of a bank's customers to learn about a variety of attitudinal and demographic issues. The stratification is to be based on savings account balances as of January 30, 2013. A frequency distribution showing the number of accounts in each stratum, together with the standard deviation of account balances by stratum, follows.

a. Assuming the cost per unit sampled is approximately equal across strata, determine the total number of persons to include in the sample. Assume we want a bound on the error of estimate of the population mean for savings account balances of B = $20.
b. Use the Neyman allocation procedure to determine the number to be sampled for each stratum.

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Standard Deviation of Account Balances 80 150 220 700 3000 Stratum () Accounts 0.00-1,000.00 1,000.01-2,000.00 2,000.01-5,000.00 5,000.01-10,000.00 3000 600 250 100 50 over 10,000.00