Riemann sum

Hello there, can anyone help me here as I'm finding it difficult to tackle this question.

Consider f(x)=x^3 on the interval [1,5].
Find the Riemann sum for the equipartition P=(1,2,3,4,5) into 4 intervals with x_i^* being the right-hand endpoints (ie. x_i=a+hi)

Then find a formula for the Riemann sum for an equipartition P_n into n intervals and right-hand endpoints. Use the summation formulae
sum(i^3)=1/4n^2(n+1)^2, upper lim=n, lower lim;i=1.

Cheers