Question

After a special medicine is introduced into a petri dish full of bacteria, the number of bacteria remaining in the dish decreases rapidly. The relationship between the elapsed time,t, in seconds, and the number of bacteria, B(t), in the petri dish is modeled by the following function:

B(t)=9,300•(1/64)^t

Complete the following about the rate of change of the bacterial culture. Round your answer to two decimal places.

The bacterial culture loses 1/2 of its size every _________ seconds.

Answer 1

.17

Explanation:

Answer 2

0.17

Explanation:

The function can be rewritten as ...

B(t) = 9300·((1/2)^6)^t = 9300·(1/2)^(6t)

In order to multiply the number of bacteria by 1/2, the value of the exponent 6t must be equal to 1:

6t = 1

t = 1/6 ≈ 0.166667 ≈ 0.17

The culture loses half its size every 0.17 seconds.