Question

Question 4 1.25 pts Expedia would like to test the hypothesis that the average roundtrip airfare between Philadelphia and Paris is higher for a flight originating in Philadelphia when compared to a flight originating in Paris. The following data summarizes the sample statistics for roundtrip flights originating in both cities. Do not assume that the population variances are equal. Originating City Philadelphia $1,240 Paris $1,060 Sample mean Sample size Population standard deviation 15 19 $270 $240 If Population 1 is defined as flights originating in Philadelphia and Population 2 is defined as flights originating in Paris, the 90% confidence interval for the difference in population means is (-$38.95, $398.95) ($92.42, $267.58) ($136.21, $223.79) O($33.9, $326.1) ($32.43, $308.56)

Answer 1

mean Sample Sample mean Philadelphia (x1) Pariis $1, 240 $1,060 15 Sample size (no) Philadelphia Sample size (12) =19 → Paris Population standard deviation (Philadelphia ) () = $270 (Paris) (52) = = $240 Difference in population means follow Standard normal distribution. Hence, Z value for 90%. Confidence Interval Z = 1 645 TO calculate we will 90% confidence interval for differences in population mean, the following formula: (x,- T) I Z 4 N2 ( 240)² + 19 (1240 - 1060) I 10 645 (270)² 15 180 + 1.645 (88.83) ( $33.9, $326.1) ► option 4 11