You have a bit of a gambling problem. After a string of losses, betting on just about anything

that moved, you owe Jeff your neighborhood bookie $$50,000.$

Jeff won't let you bet anymore, but he offers you a payment plan. After carefully considering that

you don't want Jeff to break your legs you agree to the payment plan.

On the $1^{st}$ and ${15}^{th}$ of each month, you'll pay Jeff $$1350.$ You will do this for $3$ years. Today is

the first of the month and Jeff wants the first payment today.

What interest rate is Jeff charging you?

Enter your formula in cell A$9.$