The proportion of people who respond to a certain mail-order solicitation is a continuous random variable X that has the density function

f(x) = { 2/5( x +2) 0 < x<1, 0 elsewhere

1. Show that P(0 < X <1) = 1
2. Find the probability that more than 1/4 but fewer than 1/2 of the people contacted will respond to this type of solicitation
3. Find the cumulative distribution function F(x) then use F(x) to find P(1/4< X <1>