Bills Cell phone bills (rounded to the nearest dollar) for the most recent month for random samples of college men (M) and college women (F) were studied. Histograms for the numbers of dollars for men and women (A) and output from a Mann-Whitney test (B) are given.
a. Why would it be inappropriate to compare means with a t-test?
b. A student feels that women talk more on their phones than men and therefore have higher bills. Test this hypothesis at a 5% significance level.

12 0 75 150 225 300 375 450 Bill for men (dollars) 12 0 0 75 150 225 300 375 450 Bill for women (dollars) Mann-Whitney Test and CI: , F N Median M 23 4B.DO F 24 57.50 point estimate for ETAI-ETA2 is -5 .50 95.1 percent C1 for ETA1-ETA2 is {-18.00, 5.00} W 501.0 Test of ETA1 -ETA2 vs ETA1 ETA2 s significant at 0.1413 The test 8 8ignificant at 0.1411 (adjusted for ties)