1) An automobile dealer sells used cars with an average value of $12400. The prices are normally distributed with a standard deviation of $3280. What percentage of the cars will sell for $15000 or more?
2) Let X be an exponentially distributed random variable such that P( X > 1) = 0.367879. Find E(X).
3) A random variable X has gamma distribution with parameters alpha = 2 and beta = 3. Find P(6< x < 12 ).