Posted by Anonymous on .
An artifact was found and tested for its carbon14 content. If 74% of the original carbon14 was still present, what is its probable age (to the nearest 100 years)? Use that carbon14 has a halflife of 5,730 years.
1 yr

applied algebra 
Steve,
the fraction left after t years is
(1/2)^(t/5730)
so, you need to solve for t:
.74 = (1/2)^(t/5730)
ln .74 = t/5730 * ln .5
t = 5730 * ln .74/ln .5
t = 2489, or 2500 years