Many states have attempted to reduce the blood-alcohol level at which a driver is declared to be legally drunk. There has been resistance to this change in the law by certain business groups who have argued that the current limit is adequate. A study was conducted to demonstrate the effect on reaction time of a blood-alcohol level of 0.1%, the current limit in many states. A random sample of 22 persons of legal drinking age had their reaction times recorded in a standard laboratory test procedure before and after drinking a sufficient amount of alcohol to raise their blood alcohol to a 0.1% level. The difference (After - Before) is recorded below (in ascending order).

5. Many states have attempted to reduce the blood-alcohol level at which a driver is declared to be legally drunk. There has been resistance to this change in the law by certain business groups who have argued that the current limit is adequate. A study was conducted to demonstrate the effect on reaction time of a blood-alcohol level of 0.1 %, the current limit in many states. A random sample of 22 persons of legal drinking age had their reaction times recorded in a standard laboratory test procedure before and after drinking a sufficient amount of alcohol to raise their blood alcohol to a 0.1% level. The difference (After Before) is recorded below (in ascending order). 0.02 0.04 0.05 0.07 0.11 0.16 0.22 0.27 0.28 0.28 0.29 0.30 0.31 0.31 0.32 0.34 0.35 0.37 0.38 0.39 0.39 0.40 a. Give a 99% confidence interval estimate of both the mean and the median differences in reaction times of drivers who have a bloodalcohol level of 0.1 %. b. Is there sufficient evidence that a blood-alcohol level of 0.1% causes any increase in the mean reaction time? Justify your answer. c. Is there sufficient evidence that a blood-alcohol level of 0.1% causes any increase in the median reaction time? Justify your answer. d. The lobbyist for the business group has his expert examine the experimental equipment and determines that measurement errors may have been made when recording reaction times. Unless the median difference in reaction time is at least 0.25 seconds, the expert claims that the two times are essentially equivalent. Is there sufficient evidence that the median difference in reaction times is greater than 0.25 seconds? Iustify your