Question

1. Which of the following models is an exponential decay model?

a) y = 12 (3.57)^t
b) y = 4 (1.21)^t
c) y = 1 + 6t
d) y = 7 (0.98)^t

2. Which of the following models is an exponential decay model?
A) y = 2,000 (0.07)^t
B) y = 4,000 (3.84)^t
C) y = 26t^2
D) y = 1 + 17t

3. Exponential decay models have a base between ____ and ____.

Answer 1

1. d)
`\mathsf{y=7(0.98)^t}`

2. A)
`\mathsf{y=2000(0.07)^t}`

3. zero and 1

Explanation:

General form of an exponential model:
`\mathsf{y=ab^x}`

If 0 < b < 1 then model decays

1. d)
`\mathsf{y=7(0.98)^t}`

2. A)
`\mathsf{y=2000(0.07)^t}`

3. Exponential decay models have a base between 0 and 1