The distance between major cracks in a highway follows an exponential distribution with a mean of 8 miles. (a) what is the probability that there are no major cracks in a 10-mile stretch of the highway? (round your answer to 4 decimal places.) (b) what is the probability that there are 2 major cracks in a 10-mile stretch of the highway? (round your answer to 4 decimal places.) (c) what is the standard deviation of the distance between major crack