1.The length of time that a car lasts follows an exponential distribution with a mean of 7 years. A sample of 40 cars is received for analysis. (a). What is the rate parameter and standard deviation (b). What is the distribution for the mean length of time that the 40 cars will last? (c). What is the probability that the sample mean is less than 6.5 years (d). Determine the interquartile range for the mean length of time that the 40 cars will last