To illustrate the effects of driving under the influence(DUI) ofalcohol, 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 nineteenagers, 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 approximately normally distributed with no outliers.

Subject Normal, XiImpaired, Yi

14.475.77

24.245.67

34.585.45

44.655.32

54.315.83

64.805.49

74.595.23

85.005.63

94.795.63

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

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

1. This is a good idea in designing the experiment because the sample size is not large enough.

1. This is a good idea in designing the experiment because reaction times are different.

1. Use a95% 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 minusnormal."

The lower bound is:____

The upper bound is:____

(Round to the nearest

thousandth asneeded.)

1. State the appropriate conclusion. Choose the correct answer below.

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

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