Final answer:
The mode of the speed distribution is 48 mph. The range of speed values is from 12 mph to 84 mph. The coefficient of variation is 37.5%. The probability of exceeding 60 mph can be calculated using the area under the normal distribution curve.
Step-by-step explanation:
A) The mode of a speed distribution is the value that appears most frequently. In this case, since the speed distribution is normally distributed, the mode will be the same as the mean. Therefore, the mode of the speed distribution is 48 mph.
B) The range of speed values can be calculated by finding the difference between the maximum and minimum values. In this case, the maximum value will be the mean plus three times the standard deviation, and the minimum value will be the mean minus three times the standard deviation. Therefore, the range of speed values is from 48 mph minus (3 times 18 mph) to 48 mph plus (3 times 18 mph).
C) The coefficient of variation is a measure of relative variability and is calculated by dividing the standard deviation by the mean and multiplying by 100. In this case, the coefficient of variation is (18 mph / 48 mph) * 100.
D) To identify the probability of exceeding 60 mph, we need to find the area under the normal distribution curve to the right of 60 mph. This can be done using a standard normal distribution table or a calculator. The probability can be interpreted as the percentage of data points that are above 60 mph in a large data set.