Mikayla is planning for retirement, and she estimates that she'll want to be able to withdraw $1,000 each week for 23 years once she retires. She opens a Roth IRA and finds investments that she expects to return 2.6% interest compounded weekly. (a) How much will she need to have in the account when she retires in order to meet her goal? $ (b) How much will she have to deposit each week for the next 40 years in order to get this balance at retirement? $ (c) How much interest will her deposits earn between now and retirement? $