> Investment math problem help?

Investment math problem help?

Posted at: 2014-12-05 
Compound Annual Growth Rate (CAGR) = (fv/pv) ^ (1/t) - 1

= (4500/2400) ^ (1/4) - 1

= 0.17017366 or about 17.02%

Take the 4th-root of each side.

1.875^(1/4) = 1 + i

Stanley Roper has $2,400 that he is looking to invest. His brother approached him with an investment opportunity that could give Patrick $4,500 in 4 years. What interest rate would the investment have to yield in order for Stanley’s brother to deliver on his promise?

investment today= PV= 2400

amount to be received= FV=4500

time of investment= 4 years

returns on investment= i

FV= PV(1+i)^n

4500=2400(1+i)^4

4500/2400=(1+i)^4

1.88=(1+i)^4

I don't know what to do here... Help please