Question

A dose of a new pharmaceutical drug is decaying according to the half-life model f(t) = Ne-0.2174, where N is the dose

amount in milligrams and t is time in hours. At t = 6, there are 4 milligrams remaining. What was the dose amount in
milligrams? Round your answer to the nearest tenth, and do not include units.

Answer 1

14.7

Explanation:

Perhaps your equation is ...

f(t) = N·e^(-0.2174t)

We want f(6) = 4, so ...

4 = N·e^(-0.2174·6) = N·e^-1.3044 ≈ 0.2713N

N = 4/0.2713 = 14.7 . . . . milligrams

The dose amount was about 14.7 mg.