Suppose mu_1 and mu_1 are true mean stopping distances at 50 mph for cars of a c
ID: 3227364 • Letter: S
Question
Suppose mu_1 and mu_1 are true mean stopping distances at 50 mph for cars of a certain type equipped with two different types of braking systems. The data follows: m -6, x = 114.7, s_1 = 5.03, n = 6, y = 129.9, and s_1 = 5.32. Calculate a 95% Cl for the difference between true average stopping distances for cars equipped with system 1 and cars equipped with system 2. Does the interval suggest that precise information about the value of this difference is available? Because the interval is so narrow, it appears that precise information is available. Because the interval is so narrow, it appears that precise information is available. Because the interval is so narrow, it appears that precise information is available. Because the interval is so narrow, it appears that precise information is available. You may need to use the appropriate table in the Appendix of Tables to answer this question.Explanation / Answer
The statistical software output for this problem is:
Two sample T confidence interval:
1 : Mean of Population 1
2 : Mean of Population 2
1 - 2 : Difference between two means
(without pooled variances)
95% confidence interval results:
Hence,
95% confidence interval will be:
(-21.86, -8.54)
Option A is correct (If not then Option C)
Difference Sample Diff. Std. Err. DF L. Limit U. Limit 1 - 2 -15.2 2.9889602 9.968744 -21.86265 -8.5373501