Answer:
Exponential
Explanation:
Starter:
According to the title:
"Every day, half a bacteria population dies."
Exponential: y = ab^x ( b > 0 , b ≠ 1)
So the answer is C.
Calculations:
An exponential model is of the form y = a • b^t.
If you start with population of 500 million bacteria
t = 0
so 500 million = a • b^0 = a
Since every day half the population dies then in 1 day population will be 250 million
so a = 500 million, y = 250 million and t = 1
250 million = 500 million • b^1
b = 0.5
Therefore your equation would be
y = 500 million (or whatever the pop) • 0.5^t
Where t = number of days
This could also be written in exponential form ( e = 2.73)