If the problem means a monthly interest rate of 1.3% then
P = Po*(1.013)^(12*8)
P = 7000*(1.013^96)
P = 7000*3.45546703828
P = 24188.2692679
but it's money so:
P = 24188.27
that's the total, but the question asks for interest, so we have to subtract out the 7000 we started with
Pinterest = 24188.27 - 7000
Pinterest = 17188.27
Answer: $17,188.27