Exhibit 19-4
A company advertises that food preparation time can be significantly reduced with the Handy Dandy Slicer. A sample of 12 individuals prepared the ingredients for a meal with and without the slicer. You are given the preparation times below.
-Refer to Exhibit 19-4. The test statistic equals
A)-0.81 or 0.81
B)-0.89 or 0.89
C)-10 or 10
D)-20 or 20

Question

Exhibit 19-4
A company advertises that food preparation time can be significantly reduced with the Handy Dandy Slicer. A sample of 12 individuals prepared the ingredients for a meal with and without the slicer. You are given the preparation times below. 
-Refer to Exhibit 19-4. The test statistic equals
A)-0.81 or 0.81 
B)-0.89 or 0.89 
C)-10 or 10 
D)-20 or 20

Quizplus · Accepted Answer

Since we want to test if the Handy Dandy Slicer reduces food preparation time, we need to use a two-tailed t-test. The formula for the test statistic is (x̄1 - x̄2) / (s_p * sqrt(1/n1 + 1/n2)), where x̄1 and x̄2 are the sample means, s_p is the pooled standard deviation, and n1 and n2 are the sample sizes. Using the given data, we get a test statistic of -0.89 or 0.89 depending on the direction of the hypothesis. However, we only need to choose one value, and since the options are given in absolute value, we choose 0.89.

Exhibit 19-4 A Company Advertises That Food Preparation Time Can Be Significantly