Several hundred students enrolled in introductory statistics courses at a large university were surveyed on various days of the week and asked to report the number of minutes they'd spent talking on the phone the day before.
a. Use software to access the survey data and construct a 95% confidence interval for the mean number of minutes on the phone for the population of students.
b. According to the American Time Use Survey published by the Bureau of Labor Statistics, the mean daily time on the phone for Americans aged 15 to 24 at that time (2003) was 14.4 minutes. Use your confidence interval to decide whether or not this is a plausible value for mean daily amount of phone time for the population of students. If it is not plausible, tell whether the population of students talk on the phone more or less than Americans aged 15 to 24 in general.
c. Use mathematical notation to write null and alternative hypotheses to test if the population mean time for students could be 14.4 minutes.