In: Statistics and Probability
A researcher is interested in finding a 99% confidence interval for the mean number minutes students are concentrating on their professor during a one hour statistics lecture. The study included 105 students who averaged 38.1 minutes concentrating on their professor during the hour lecture. The standard deviation was 11.2 minutes. Round answers to 3 decimal places where possible.
a. To compute the confidence interval use a ? z t distribution.
b. With 99% confidence the population mean minutes of concentration is between and minutes.
c. If many groups of 105 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 mean minutes of concentration and
about percent will not contain the true population mean
minutes of concentration.