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 141 students who averaged 25.7 texts per day. The standard deviation was 21.2 texts. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a tv distribution. 0 and b. With 95% confidence the population mean number of texts per day is between texts. c. If many groups of 141 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. Question Help: Message instructor Submit Question

Answer 1

i am using minitab to solve the problem

1).steps:-

copy the data in minitab and name the column x stat basic statistics 1-sample T select summarized data from the drop down menu type 141 in sample size, 25.7 in sample mean,21.2 in standard deviation  tick perform hypothesized test options in confidence level type 95 select alternative hypothesis as mean $\neq$ hypothesized mean okok.

*** SOLUTION ***

a). we will use t distribution.

b). with 95% confidence the population mean number of texts per day is between 22.170 and 29.230

c).If many groups of 141 randomly selected members are studied, then a different confidence interval would be produced from each group. About 95 percent of these confidence intervals will contain the true population number of texts per day and about (100-5) = 5 percent will not contain the true population mean number of texts per day.

2).steps :-

copy the data in minitab and name the column x stat basic statistics 1-sample T select one or more samples, each in a column from the drop down menu in the blank box below select x tick perform hypothesized test options in confidence level type 95 select alternative hypothesis as mean $\neq$ hypothesized mean okok.

*** SOLUTION***

a). we will use t distribution.

b). with 95% confidence the population mean number of days of class that college students miss is between 4.062 and 8.861.

c).If many groups of 13 randomly selected non-residential college students are surveyed, then a different confidence interval would be produced from each group. About 95 percent of these confidence intervals will contain the true population mean number of missed class days and about (100-95) = 5 percent will not contain the true population mean number of missed class days.

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