Question

A researcher is interested in finding a 95% confidence interval for the mean number of times per day that college students text. The study included 125 students who averaged 36.6 texts per day. The standard deviation was 21.6 texts. Round answers to 3 decimal places where possible.

a. To compute the confidence interval use a ? z t  distribution.

b. With 95% confidence the population mean number of texts per day is between  and   texts.

c. If many groups of 125 randomly selected members are studied, then a different confidence interval would be produced from each group. About  percent of these confidence intervals will contain the true population number of texts per day and about  percent will not contain the true population mean number of texts per day.

Answer 1