P is the principal amount, $5200.00.
r is the interest rate, 6% per year, or in decimal form, 6/100=0.06.
t is the time involved, 9....year(s) time periods.
So, t is 9....year time periods.
To find the simple interest, we multiply 5200 × 0.06 × 9 to get that:
The interest is: $2808.00