Pavani is saving for her retirement. She just turned 27 and plans to retire when she is 65. She wants to have $4 million when she retires. The nominal annual interest rate is 11% compounded semi-annually.(All answers to 2 decimal places. Keep at least 5 decimal places for intermediate calculations.)

a) How much will she have to save every six months if she starts saving today? (Assume her final payment is six months before she turns 65).

b) How much will she have to save every six months if she doesn't start saving until 4 years from today?

c) If the interest rate were 10%, how much would she have to save every six months if she starts saving today? (Again, assume her final payment is six months before she turns 65.)