I'm not sure why my answer is not correct. ()last one only)

Please explain your work briefly... :(

"Time headway" in traffic flow is the elapsed time between the time that one car finishes passing a fixed point and the instant that the next car begins to pass that point. Let X = the time headway for two randomly chosen consecutive cars on a freeway during a period of heavy flow (sec). Suppose that in a particular traffic environment, the distribution of time headway has the following form. F ( x ) x > 1 xs1 (a) Determine the value of k for which f(x) is a legitimate pdf. 5 (b) Obtain the cumulative distribution function. F (x) = 1 -x -5 x> 1 x$1 (c) Use the cdf from (b) to determine the probability that headway exceeds 2 sec. (Round your answer to four decimal places.) 0.03125 Use the cdf from (b) to determine the probability that headway is between 2 and 3 sec. (Round your answer to four decimal places.) 0.02713 V (d) Obtain the mean value of headway and the standard deviation of headway. (Round your standard deviation to three decimal places.) mean 1.25 standard deviation 0.3227 (e) What is the probability that headway is within 1 standard deviation of the mean value? (Round your answer to three decimal places.) 1.35 X