It would help if you proofread your questions before you posted them. The information below only applies to a normal distribution. Your data do not indicate a normal distribution. Anything over 1.2 SD below the mean would be negative.
95% = mean ± 1.96 SEm
SEm = SD/√n
A recent poll of a random sample of 400 students at a public 4-year college showed the average (mean) amount of time spent using email was 49 minutes per day with a standard deviation of 44 minutes.
a. find a 95% confidence interval fot the population mean
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1 answer