Question

A car company wishes to test the claim that at an average of 55 mph, the stopping distance for auto brakes is 130 ft. In a random sample of 12 individuals that were tested for their breaking distance were recorded, a sample mean of 114 ft. Based on the previous records, the standard deviation is recorded as 20 ft. At the 10% level of significance, test the claim that the stopping distance for a car traveling at 55 mph is less than the stated 130 ft.

What is the Null hypothesis (H0); Alternate hypothesis (H1); and the direction of the test?                            [ Select ]                       ["mu=130; mu<130; right tail Test", "mu=130; mu>130; left tail Test", "mu=130; mu<130; left tail Test", "mu=130; mu<130; two tail Test"]      

Which distribution is used in this case?                            [ Select ]                       ["t with 10 d.f", "z", "t with 11 d.f", "Both"]      

What is the critical value?                            [ Select ]                       ["1.28 and -1.28", "1.28", "2.58", "-1.28"]      

What is the Test Statistic Value?                            [ Select ]                       ["-2.77", "3.32", "1", "2.77"]      

What is the P-value?                            [ Select ]                       ["0.001<pvalue<0.01", "0.0029", "0.001", "0.05"]      

What is the conclusion of the test?                            [ Select ]                       ["Test is Incomplete", "Test is Significant", "Test is Insignificant", "Test is Significantly Sufficient"]      

Answer 1

Hence, there is enough evidence to conclude that the stopping distance for a car traveling at 55 mph is less than the stated 130 ft at 10% level of significance.