can someone correct these for me thanks..

Problem #4
Find the effective rate corresponding to the given nominal 18% compounded quarterly.

My answer: 19.2%

Problem #7
Find the future value of the ordinary annuity If R= $2500,I=5% interest compounded quarterly for 16 years.

My answer: Future value $59,143.72

Problem#10
Find the present value of the ordinary annuity payments of $17000 annually for 10 years at 12% compounded annually.

my answer $1,184,908.87

10. Obviously wrong. 17,000 x 10 years is 170, 000 and the present value cannot be more than that.

7. No, I get considerably less than that.

You can check these yourself at
http://www.uic.edu/classes/actg/actg500/pfvatutor.htm