Answer:
The 99% confidence interval for the true mean amount of time Americans spend social networking each day is (3.02 hours, 3.36 hours).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for population mean when the population standard deviation is not known is:
The information provided is:
Confidence level = 99%.
Compute the critical value of <em>t</em> for 99% confidence interval and (n - 1) degrees of freedom as follows:
*Use a <em>t</em>-table.
Compute the 99% confidence interval for the true mean amount of time Americans spend social networking each day as follows:
Thus, the 99% confidence interval for the true mean amount of time Americans spend social networking each day is (3.02 hours, 3.36 hours).