Q:Question:9. The Bank of New England is concerned about the amount of debt being accrued by customers using its credit cards. The Board of directors decided to install an expensive monitoring system if the mean for all the bank's customers is greater than $2000. The bank randomly selected 1 0 0 credit card holders and determined the amounts they charged. For this sample group the mean is $ 2180 and standard deviation is $ 8 4 5. Use 0.05 level ofA:Answer:ANSWER: Given Mean(x?) = 2180 Standard deviation(?...