Reference no: EM13105028
Every six months, the United States Federal Reserve Board conducts a survey of credit card plans in the U.S. The following data are the intrest rates charged by 10 credit card issuers randomly selected for the January 2008 survey. The population mean credit card interest rate in January 2008 was 13.5%, and the population standard deviation was 3.2%. Institutions:
(Pulaski Bank and Trust Company, rate 6.5%),(Rainier Pacific Savings Bank, rate 12.0%),(Wells Fargo Bank NA, rate 14.4%), (Firstbank of Colorade, rate 14.4%), (Lafayette Ambassador Bank, rate 14.3%),(Infibank, rate 13.0%), (United Bank, Inc, rate 13.3%), (First Natinal Bank of the Mid Cities, rate 13.9%), (Bank of Louisiana, rate 9.9%), (Bar Harbor Bank and Trust Company, rate 14.5%).
A) Use the population mean and standard deviation to find the z-score corresponding to 6.5%, the rate offered by the Pulaski Bank and Trust Company.
B) Use the population mean and standard deviation to find the z-score corresponding to 14.5%, the rate offered by the Bar Harbor Bank and Trust Company. Is this above or below the average?
C) Find the interquartile range of the interest rates.