Americans have become increasingly concerned about the rising cost of medicare. in 1990, the average annual medicare spending per enrollee was $3267; in 2003, the average annual medicare spending per enrollee was $6883 (money, fall 2003). suppose you hired a consulting firm to take a sample of fifty 2003 medicare enrollees to further investigate the nature of expenditures. assume the population standard deviation for 2003 was $1800. when calculating values for z, round to two decimal places. calculate the standard error of the mean amount of medicare spending for a sample of fifty 2003 enrollees (to 2 decimals). what is the probability that the sample mean will be within +/- $300 of the population mean (to 4 decimals)? what is the probability that the sample mean will be greater than $7500 (to 4 decimals)? if the consulting firm tells you the sample mean for the medicare enrollees it interviewed was $7500, would you question whether the firm followed correct simple random sampling procedures?