Question

Parking at a large university can be extremely difficult at times. One particular university is trying to determine the location of a new parking garage. As part of their research, officials are interested in estimating the average parking time of students from within the various college on campus. A survey of 338 college of business (COBA) student yields the following descriptive information regarding the length of time (in minutes) it took them to find a parking spot. Note that the "Lo 95%" and "Up 95%" refer to the endpoint s of the desired confidence interval.

Variable N Lo 95% CI Means Up 95%CI SD
Parking time 388 9.1944 10.466 11.738 11.885
Explain what the phrase "95% confident" means when working with a 95 % confidence interval.

Answer 1

The phrase "95% confident" means that there is a 95% confidence that the true mean parking time of students from within the various college on campus is included in the interval (9.1944, 11.738).

Explanation:

The (1 - α)% confidence interval for population parameter implies that there is a (1 - α) probability that the true value of the parameter is included in the interval.

Or, the (1 - α)% confidence interval for the parameter implies that there is (1 - α)% confidence or certainty that the true parameter value is contained in the interval.

From the provided data the 95% confidence interval for the population mean parking time of students from within the various college on campus is:

CI = (9.1944, 11.738)

This 95% confidence interval implies that the true mean parking time of students from within the various college on campus is included in the interval (9.1944, 11.738) with a specific probability or confidence of 95%.

Thus, the phrase "95% confident" means that there is a 95% confidence that the true mean parking time of students from within the various college on campus is included in the interval (9.1944, 11.738).