10 7 A loan officer compares the interest rates for 48-month fixed-rate auto loans and 48-month variable-rate auto loans. Two independent, random samples of auto loan rates are selected. A sample of five 48-month variable-rate auto loans had the following loan rates: points 2.40% 3.01% 2.873% 3.28% 3.13% while a sample of five 48-month fixed-rate auto loans had loan rates as follows: eBook 4.023% 3.82% 4.385% 3.78% 4.07% Print Figure 11.7 References JMP Output of Testing the Equality of Mean Loan Rates for Variable and Fixed 48-Month Auto Loans Means and Std Deviations Level Fixed Variable t Test Number 5 Mean 4.01560 5 2.93860 Variable-Fixed Assuming equal variances Std Dev 0.336407 0.241473 Difference -1.0770 t Ratio -5.81561 Std Err Dif 0.1852 DF Upper CL Dif -0.6499 Lower CL Dif Confidence -1.5041 0.95 Prob >|t| Prob > t Prob t 8 0.0004* 0.9998