I have this distribution function of a random variable X:
I wish to find E(X).
I have used derivatives to get the density function, compared it to 1, and found that f(t) = (4/5)t+(3/5). I then used integral of tf(t) over the range of 0 to 1, and got 0.56667. According to the answer I got, it's incorrect (maybe the answer is incorrect, not me?). Can you please assist? Thank you !