Sally has $800,000 in her savings fund. She rolls her money into an annuity fund which earns 4.7% p.a. compounded monthly. She wants to withdraw $7000 each month to live on.

a) How long will her money last?

b) "How much longer" would her money last if she only withdraw $6000 each month? I need to define the following values to enter in TI84 calculator N = I = PV = PMT = FV = P/Y = CIY = I have to use "TVM" application to solve this (APPS -> FINANCE -> TVM solver)