From her firm’s computer telephone log, an executive found that the… From her firm’s computer telephone log, an executive found that the mean length of 64 telephone calls during July was 4.48 minutes with a standard deviation of 5.87 minutes. She vowed to make an effort to reduce the length of calls. The August phone log showed 48 telephone calls whose mean was 2.396 minutes with a standard deviation of 2.018 minutes.(a)Choose the appropriate hypotheses for a right-tailed test. Assume1is the average call length in July and2is the average call length in August.a.H0:1-2= 0 vs.H1:1-2> 0b.H0:1-2< 0 vs.H1:1-2= 0multiple choice 1ab(b-1)Obtain a test statistictcalcandp-value assuming unequal variances.(Use the quick rule to determine degrees of freedom. Round your answers to 3 decimal places.)tcalcp-value(b-2)Interpret the results usinga= .01. (Click to select) Do not reject Reject the null hypothesis.(b-3)What is your conclusion ata= .01?We (Click to select) cannot can conclude the length of calls had been reduced.(c)The sample data maynotfollow a normal distribution becausemultiple choice 4The sample standard deviations are not equal.The number of phone calls in the two samples is not equal.The distribution could be skewed to the right by one or two extremely long calls.The number of phone calls recorded was not large enough to assume normal distribution.MathStatistics and Probability DAT 565
