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**evinez** find the time required for an investment of 5000 dollars to grow to 9000 dollars at an interest rate of 7.5 percent per year, compounded quarterly.

t= _____

this is what i have got so far please correct me if i am wrong

9000=5000(1+.075/4)^4t

so you divide by 5000 on each side leaving you with

9000/5000= 1.8

1.8= (1+.075/4)^4t

Ln1.8 = Ln(1+.075/4)^4t

divide by 4(1+.075/4)

$\displaystyle \ln1.8/{\color{red}(} 4\ln(1+.075/4)/{\color{red})} = t$

then whats next? cuz i got that this above part equals -.584