1. The age of professional racecar drivers is normally distributed with a mean of 30 and a standard deviation of 6. One driver is randomly selected. What is the probability that this driver is between 31 and 36 years old? a. .023 b. .878 c. .275 d. not enough information to answer 2. The age of professional racecar drivers is normally distributed with a mean of 30 and a standard deviation of 6. One driver is randomly selected. What is the probability that this driver is less than 18 years old? a. .023 b. .878 c. .275 d. not enough information to answer

3. Why is the standard deviation of the sample means less than the population standard deviation? a. It is not less; taking a group of scores at a time introduces additional error. b. The data is sampled twice, thereby reducing error. c. It is not less; smaller samples will have greater variability. d. The data is "condensed" by taking a group of scores at a time, so variability is reduced.