Question

Police trainees were seated in a darkened room facing a projector screen. Ten different license plates were projected on the screen, one at a time, for five seconds each, separated by twenty second intervals. Then the lights were turned on and the trainees were asked to write down as many of the ten license plate numbers as possible, in any order. A random sample of 15 trainees who took this test were given a weeklong memory-training course and retested. The # of plates correctly identified before and after the training are shown in the table below:

After (A)	6	8	6	7	9	8	9	6	7	5	9	8	6	8	6
Before (B)	6	5	6	5	7	5	4	6	7	8	4	5	3	6	7
Difference (A-B)

At the 10% level of significance, test the hypothesis that the memory course improved the ability of trainees to correctly identify license plates.

Suppose we wanted to test Ho: μd ≤ 1 versus Ha: μd >1 instead. (Problems 17-19)

Find the test statistic

	a.	The correct answer does not appear as one of the choices.
	b.	-.9385
	c.	1.533
	d.	.9385
	e.	.9067

Answer 1