Terri Vogel, an amateur motorcycle racer, averages 129.62 seconds per 2.5 mile lap (in a 7 lap race) with a standard deviation of 2.29 seconds. The distribution of her race times is normally distributed. We are interested in one of her randomly selected laps. (Source: log book of Terri Vogel) Let X be the number of seconds for a randomly selected lap. Round all answers to 4 decimal places where possible. a. What is the distribution of X? X ~ N( 129.62, 2.29) b. Find the proportion of her laps that are completed between 129.4 and 131.75 seconds. c. The fastest 2% of laps are under seconds. d. The middle 40% of her laps are from seconds to seconds.
