Stanley Roper has $2,100 that he is looking to invest. His brother approached him with an investment opportunity that could give Patrick $4,500 in 4...

Stanley Roper has $2,100 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? (Answer needs to be stated as a decimal. For example: .1192)