Assume That the National Credit Card Interest Rate Is 12

Multiple Choice

Assume that the national credit card interest rate is 12.83 percent.A study of 81 college students finds that their average interest rate is 15 percent with a standard deviation of 8.7 percent.What is the 95 percent confidence interval for this single-sample t test?

A) [10.54, 19.54]
B) [11.64, 16.36]
C) [12.99, 15.01]
D) [13.08, 16.92]