The reaction time (in seconds) to a certain stimulus is a continuous random variable with pdf: 0 x

The reaction time (in seconds) to a certain stimulus is a continuous random variable with pdf: a 2 x a.) Find a such that f(x) is a legitimate pdf. b.) Find the cdf. c.) What is the probability that the reaction time is at most 2.5 seconds? d.) What is the probability that the reaction time is between 1.5 and 2.5 seconds? e.) Find the expected reaction time.