1. ## A quick question about log

70=2.5(1.07)^t

t=49.25

How do I find this? How do I solve for t in a situation like this?

2. Originally Posted by Dave J
70=2.5(1.07)^t

t=49.25

How do I find this? How do I solve for t in a situation like this?
Divide both sides by 2.5,
$(1.07)^t=70/2.5=28$
Take logarithm of both sides,
$\log 1.07^t = \log 28$
$t\log 1.07=\log 28$
$t=\frac{\log 28}{\log 1.07}\approx 77.25$