According to a recent survey, women chat on their mobile phones
more than do men. 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,...