A bank wonders whether omitting the annual credit card fee for customers who charge ar least $3000 in a year will increase the amount charged on its cards. The bank makes this offer to an SRS of 400 of its customers. It then compares how much these customers charge this year with the amount they charged last year. The mean increase in the sample $246 and the standard deviation is $112. Is there significant evidence at the 1% level that the mean amount charged increases under the no-fee offer? State Ho and Ha and carry out a significance test. Use significance level 0.01
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