The formula is
A=p (1+r)^t
A future value 6678
P present value 5300
R interest rate 0.065
T time?
6678=5300 (1+0.065)^t
6678/5300=(1+0.065)^t
Take the log for both sides
Log (6678/5300)=t×log (1+0.065)
Divide both sides by log (1+0.065)
T=(log(6,678÷5,300)÷log(1+0.065))
T=3.7 years
Hope it helps!