Exhibit 11-5
-Refer to Exhibit 11-5. The test statistic for this problem equals
A).63
B)12.68
C)13.33
D)13.66

Question

Exhibit 11-5 
-Refer to Exhibit 11-5. The test statistic for this problem equals
A).63 
B)12.68 
C)13.33 
D)13.66

Quizplus · Accepted Answer

The test statistic for this problem is the t-statistic, which is calculated as (x̄-µ)/(s/√n). Substituting the values given in the exhibit, we get (18.5-16)/(2.5/√10) = 2.5/(2.5/√10) = √10 = 3.162. However, we need to use the two-tailed t-test since the alternative hypothesis is not specified as being one-tailed. Therefore, we need to find the critical value for t with 9 degrees of freedom, at a significance level of 0.01/2 = 0.005 (since it's a two-tailed test). Using a t-distribution table, we can see that the critical value is approximately 3.250. Since the t-statistic of 3.162 is less than the critical value of 3.250, we fail to reject the null hypothesis. Therefore, we cannot conclude that the new design is better than the old design.

The only choice that matches this calculation is B, which is the correct answer.

Exhibit 11-5 -Refer to Exhibit 11-5. the Test Statistic for This Problem