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 138 students who averaged 27.3 texts per day. The...

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 138 students who averaged 27.3 texts per day. The standard deviation was 17.9 texts. Round answers to 3 decimal places where possible.

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

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

c. If many groups of 138 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.