Question

what is the decay rate in the following model? a=1200(.85)^6 1200 .15 6 .85

Explanation:

Step1: Recall decay formula

The exponential decay model is \( A = P(1 - r)^t \), where \( P \) is the initial amount, \( r \) is the decay rate, and \( t \) is time.

Step2: Compare with given model

Given \( A = 1200(0.85)^6 \), compare with \( A = P(1 - r)^t \). Here, \( 1 - r = 0.85 \).

Step3: Solve for decay rate \( r \)

Subtract \( 0.85 \) from \( 1 \): \( r = 1 - 0.85 = 0.15 \).

Answer:

\( 0.15 \) (corresponding to the option with \( 0.15 \))