According to a recent survey, women chat on their mobile phones more than men (CNN.com, August 25, 2010). To determine if the same patterns also exist in colleges, Irina takes a random sample of 40 male students and 40 female students in her college. She finds that female students chatted for a sample average of 820 minutes per month, with a sample standard deviation of 160 minutes. Male students, on the other hand, chatted for a sample average of 760 minutes per month, with a sample standard deviation of 240 minutes. It is not reasonable to assume equal population variances.
A) Obtain a 95% confidence interval for the difference between the average amount of chat time for males and the average amount of chat time for females.
B) Make a conclusion at the 5% significance level.

Question

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The Answer of According to a recent survey, women chat on their mobile phones more than men (CNN.com, August 25, 2010). To determine if the same patterns also exist in colleges, Irina takes a random sample of 40 male students and 40 female students in her college. She finds that female students chatted for a sample average of 820 minutes per month, with a sample standard deviation of 160 minutes. Male students, on the other hand, chatted for a sample average of 760 minutes per month, with a sample standard deviation of 240 minutes. It is not reasonable to assume equal population variances.
A) Obtain a 95% confidence interval for the difference between the average amount of chat time for males and the average amount of chat time for females.
B) Make a conclusion at the 5% significance level.

According to a Recent Survey, Women Chat on Their Mobile