James has set up an ordinary annuity to save for his retirement in 19 years. If his monthly payments are $250 and the annuity has an annual interest rate of 7.5%, what will be the value of the annuity when he retires?

I am studying for my math final and I do not remember how to do ordinary annuities. I remember that the equation is:

A=R{1+r/m}^mt-1(r/m)

How do I plug this equation in?

Would it start out like,

A= 250(1+.75/12)^mt-1/(r/m)

Thanks