Question 662335
A = P(1+ r/n)^nt
here P is principal amount=5000
r=interest rate as decimal=0.075
and n=number of times the interest is compounded per year=4
t= number of years=? and A=amount of money accumulated after t years, including interest=6200 dollars

substitute these values in that formula 
6200=5000(1+0.075/4)^(4t)
6200/5000=1.01875^4t => 1.01875^4t=31/25
ln(1.01875)^4t=ln (31/25)
4t(ln 1.01875)=ln(31/25)
=>t= ln(31/25)/(4ln 1.01875)=2.895 that is approximately 3 years