Question

A professor claims that the average grade of students in her courses is 80%. Identify the confidence for this claim.

A. Reject the claim that average grade is 80% when it is actually 80%.
B. Fail to reject the claim that average grade is 80% when it is actually different from 80%.
C. Reject the claim that average grade is 80% when it is actually different from 80%.
D. Fail to reject the claim that average grade is 80% when it is actually 80%.

Answer 1

A. Reject the claim that average grade is 80% when it is actually 80%.

Explanation:

The confidence interval is a mathematical indicator which makes it possible to quantify the zone of uncertainty, during a survey or a poll on a sample of the population. The more representative this sample, the smaller the confidence interval, and the closer the survey result will be to reality. The confidence interval makes it possible to determine the margin of error of the sample chosen, to estimate what the real result would have been by enclosing it in a range.

So, the correct identification of the confidence for the claim made by the professor is to:

Reject the claim that average grade is 80% when it is actually 80%.