Question

Refer to the accompanying data set of mean drive-through service times at dinner in seconds at two fast food restaurants. Construct a 95% confidence interval estimate of the mean drive-through service time for Restaurant X at dinner, then do the same for Restaurant Y. Compare the results. Click the icon to view the data on drive-through service times. Construct a 95% confidence interval of the mean drive-through service times at dinner for Restaurant X sec<u<sec (Round to one decimal place as needed.) Construct a 95% confidence interval of the mean drive-through service times at dinner for Restaurant Y. sec <μ</sec (Round to one decimal place as needed.) Compare the results. O A. The confidence interval estimates for the two restaurants overlap, so there does not appear to be a significant difference between the mean dinner times at the two restaurants. OB. The confidence interval estimates for the two restaurants do not overlap, so there does not appear to be a significant difference between the mean dinner times at the two restaurants. OC. The confidence interval estimates for the two restaurants overlap, so it appears that Restaurant Y has a faster mean service time than Restaurant X. OD. The confidence interval estimates for the two restaurants do not overlap, so it appears that Restaurant Y has a faster mean service time than Restaurant X

Answer 1

Restaurant x, W = 176.88 Sample Miseln) - 50 Sample mean Sample st. deviation (n) = 61,09 The 95% confidence interval of the mean drive-through service times at dinnes for Restaurant & is so att |-O.O, nt = 176.88+ 2,010x 01.09. √50 =176.88 – 17.37 = (159.51, 1 (159,57,194.25) 15.9.5 see <l < 94.3 sec. Restaurant you n=50 9 =153.74 sy=49.95 The 95% confidence interval the mean drive through service times at dinner for Restaurant y is of =153.74€ 2.010%.< g 2 & 1-0.05, n. Bylo = 153.44*14.20 =139.54,167.94) 49.95 150 = 139.5 su M. <167:9 see. Compare: Ars: A The confidence interval estinates for the two restaurants overlap, so those does not appear to be a significant difference between the dinner times at the two restaurants,

Xr0.55 0.79 0.93 1.24 0.56 0.86 ques, no net = 0.719 8= 0.36 The 95% confidence interval of the population means i ntt = 0.719 22:447x 0 36 17 =o:719 7 0.333 (0.386, 1.052) Conclusioni Aus: A. Yes because it is possible that the mean os greater than I ppm. Also, at least one of the sample valius exunds 1ppm, so at least some the tish have two much mercury. of