an investment of $75000 increases of a rate of 12.5% per year quarterly compound what would it be in 30 years?

Almost anon but not quite.

It is 12.55% per year compounded quarterly for 30 years.

that is 0.1255 per year compounded quarterly for 30 years.

BUT the real rate is 0.1255/4=0.031375 per quarter invested for 30*4=120 quarters

FV= 75000(1+0.1255)^120

75000 x 1.125 to the power of 30