Question

and are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. Use the two-sample t test at significance level 0.01 to test Hi H, - H, = -10 Suppose versus H - l, < -10 for the following data: m = 7, x = 115.8, s = 5.08, 7, y = 129,4, and s = 5.31. Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.) t =1.30 P-value State the conclusion in the problem context OReject H The data suggests that the difference between mean stopping distances is less than -10. OReject H: The data does not suggest that the difference between mean stopping distances is less than -10 O Fail to reject H. The data suggests that the difference between mean stopping distances is less than -10. OFail to reject H The data does not suggest that the difference between mean stopping distances is less than -10

Answer 1

The statistical software output for this problem is:

Two sample T summary hypothesis test: Pi : Mean of Population 1 12 : Mean of Population 2 V1 -2 : Difference between two means Ho : 11 - 12 = -10 HA: P1 - H2 < -10 (with pooled variances) Hypothesis test results: Difference Sample Diff. Std. Err. DF T-Stat P-value Pi - 12 -13.6 2.7775246 12 -1.2961181 0.1097

Hence,

P- value = 0.110

Conclusion: Option D is correct.