An insurance company wants to estimate the mean score on this exam for students who have enrolled in a special study program. They take a sample of 8 students in this program and determine that their scores are: 2, 5, 8, 8, 7, 6, 5, and 7. This sample will be used to calculate a 90% confidence interval for the mean score for students in the special study program.
a. The mean of the sample is ________, while the standard deviation of the sample is ________.
b. The confidence interval will be based on ________ degrees of freedom.
c. The critical value used in constructing a 90% confidence interval is ________.
d. Construct a 90% confidence interval for the mean score of students in the special .
e. If we use the same sample information to obtain a 95% confidence interval, the resulting interval would be narrower than the on the obtained here with 90%.