Ann and tom want to establish a fund for their grandson's college education. what lump sum must they deposit at a 12.4% annual interest rate, compounded monthly, in order to have $30,000 in the fund at the end of 15 years?

A=P(1+r/n)^(tn)
n=number of times per year compounded
A=amount
P=principal inveseted
r=rate in decimal
t=time in years

so

we want A=30000
r=12.4%=0.124
t=15
monthyl means n=12

30000=P(1+0.124/12)^(15*12)
solve for P
easy, just divide both sides by (1.01033)^180
4714.97=P
that much must be invested

Ithink you're supposed to multiply 12.50 which is how much he makes per hour and then multiply it by each number then add whats left togrther and there's your answer