it would mean alot to get assiatnce im lost precalculus

Question

A radioactive substance decays exponentially. A scientist begins with 190 milligrams of a radioactive substance. After 26 hours, 95 mg of the substance remains. How many milligrams will remain after 38 hours?

 ____mg

Give your answer accurate to at least one decimal place

Answer 1

Hi Katie!

Starting off, the exponential decay formula is P(t) = P₀e^-rt

When the initial amount is 190 mg and after 26 hours there is 95 mg left, the decay rate is 2.66% per hour.

Using that formula again but changing the information around, at 38 hours there will be 69 mg (68.99) of the radioactive mixture left.

Hope this helps!