The function t relates the age of a plant fossil, in years, to the percentage, c, of carbon-14 remaining in the fossil relative to when it was alive.
t(c)=-3,970(ln c)
Use function t to complete the statements.
A fossil with 47% of its carbon-14 remaining is approximately ___ years old.
A fossil that is 7,000 years old will have approximately ___ of its carbon-14 remaining.