To illustrate the effects of driving under the influence (DUI) of alcohol, a police officer brought a 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 recorded. Complete parts (a) and (b). Note: A normal probability plot and box plot of the data indicate that the difference are approximately normally distributed with no outliers.

Subject 1 2 3 4 5 6 7 8 9

Normal,Xi. 4.49 4.34 4.58 4.65 4.31 4.83 4.59 5.00 4.79

Impaired,Yi 5.86 5.67 5.51 5.32 5.90 5.49 5.23 5.63 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 reaction times are different.

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

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

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

Lower bound is?

Upper bound is?

(Round to the nearest thousandth as needed)

State the appropriate conclusions. Choose the correct answer below.

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

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