Question

Radium-226, in grams, decays in such a way that after t years, the amount left over can be modeled by the equation A(t)=450e−0.0004t
. How many grams of Radium-226 will remain after seven years? Round your answer to the nearest tenth.(1 point)

548.6 grams

448.7 grams

468.9 grams

344.6 grams

Answer 1

A(7) = 450e^(−0.0004·7) = 450e^(−0.0028) ≈ 450(0.9972039) ≈ 448.7 grams.

Answer: 448.7 grams.