Ahiker discovers a skull that contains 41% of its original amount of c-14. find the age of the skull to the nearest year

We need the half-life of C-14 which is 5,730 years.
Now, we will need a half-life equation:
elapsed time = half-life * log (bgng amt / ending amt) / log 2
We'll say beginning amount = 100 and ending amount = 41
elapsed time = 5,730 * log (100/41) / log 2
elapsed time = 5,730 * log ( 2.4390243902 ) / 0.30102999566
elapsed time = 5,730 * 0.38721614327 / 0.30102999566
elapsed time = 5,730 * 1.2863041851
elapsed time = 7,370.523 years

Source:
http://www.1728.org/halflife.htm