Question

To illustrate the effects of driving under the influence of alcohol, a police officer brought a DUI simulator to a local high school. Student reaction time in an emergency was measured with unimpaired vision and also while wearing a pair of special goggles to simulate the effects of alcohol on vision. For a random sample of nine teenagers, the time (in seconds) required to bring the vehicle to a stop from a speed of 60 miles per hour was recorded. Complete parts (a) and (b). Note: A normal probability plot and boxplot of the data indicate that the differences are appromixately normally distributed with no outliers.

Subject	Normal, X1	Impaired, Y1
1	4.47	5.77
2	4.24	5.85
3	4.58	5.45
4	4.65	5.32
5	4.31	5.90
6	4.83	5.49
7	4.55	5.23
8	5.00	5.61
9	4.79	5.63

(a) Whether the student had unimpaired vision or wore goggles first was randomly selected. Why is this a good idea in designing the experiment?

A)This is a good idea in designing the experiment because it controls for any "learning" that may occur in using the simulator.

B)This is a good idea in designing the experiment because reaction times are different

C) This is a good idea in designing the experiment because the sample size is not large enough

(b) Use a 95% confidence interval to test if there is a difference in braking time with impaired vision and normal vision where the differences are computed as "impaired minus normal"

The lower bound is ______

The upper bound is _______

(Round to the nearest thousandth as needed)

State the appropriate conclusion

A)There is sufficient evidence to conclude there is a difference in braking time with impaired vision and normal vision

B)There is insufficient evidence to conclude there is a difference in braking time with impaired vision and normal vision

Answer 1

a) Whether the student had unimpaired vision or wore goggles first was randomly selected. Why is this a good idea in designing the experiment?

A)This is a good idea in designing the experiment because it controls for any "learning" that may occur in using the simulator.

b).

The lower bound is 0.669

The upper bound is 1.294

State the appropriate conclusion

A)There is sufficient evidence to conclude there is a difference in braking time with impaired vision and normal vision

----------------------------------Work out---------------------------------------------------------------------------------------------------------------

We shall first calculate the differences and the sd of the difference.

student	X1	Y1	diff	diff^2
1	4.47	5.77	1.3	1.69
2	4.24	5.85	1.61	2.5921
3	4.58	5.45	0.87	0.7569
4	4.65	5.32	0.67	0.4489
5	4.31	5.9	1.59	2.5281
6	4.83	5.49	0.66	0.4356
7	4.55	5.23	0.68	0.4624
8	5	5.61	0.61	0.3721
9	4.79	5.63	0.84	0.7056
		Total	8.83	9.9917

The 95% confidence interval for teh difference is therefore