Need help with question #3

Online shopping statistics are routinely reported by www.shop.org. Of interest to many online retailers are gender-based differences in shopping preferences and behaviors. The summary data of monthly online expenditures for a sample of male and female online shoppers are shown in the following table: Male Female n 45 45 Mean $352 $310 StDev s $95 $80 Question 1. Find 95% confidence intervals for the mean monthly online expenditures for male and female online shoppers (use 2 decimal places in your answers; do not round intermediate calculations). 324.24 'I lower bound of male interval (use 2 decimal places in your answer). 379.76 upper bound of male interval (use 2 decimal places in your answer). 286.63 V lower bound of female interval (use 2 decimal places in your answer). 333.37 .I upper bound of female interval (use 2 decimal places in your answer). Question 2. The confidence intervals in question 1 overlap. If someone incorrectly interprets the meaning of this overlap, what would they conclude about gender-based differences in online expenditures? They would incorrectly conclude that the overlap is evidence that there is no signicant difference between the mean online expenditures of males and females. 3 Even though there is overlap, the samp|_e mean for males is greater so it is certain that the mean online expenditures for all males who shop online is greater than the mean online expenditures for all females who shop online. Question 3. Find the 95% condence interval for the difference in mean monthly online expenditures between males and females. lower bound of condence interval (use 2 decimal places in your answer). upper bound of condence interval (use 2 decimal places in your answer). Question 4. The results in questions 1 and 3 seem contradictory. Which method is correct: doing two-sample inference as in question 3, or doing one-sample inference twice as in question 1? Twosample inference; that is, calculate one condence interval for the difference between the means as in Question 3. V One-sample inference twice; that is, calculate a condence interval for each individual mean as in Question 1. V