Modeling Exponential Growth and Decay

What is the formula for exponential growth?

What is the formula for exponential decay?

• final amount

• time

• original amount

• rate of growth

• final amount

• time

• original amount

• rate of growth

• final amount

• time

• original amount

• rate of growth

• final amount

• time

• original amount

• rate of growth

North Dakota has recently had the fastest growing population out of all 50 states. On Jan 1, 2013, the population of North Dakota was 700,000 people. North Dakota’s population has been growing by 5% per year. Express North Dakota’s population, N, in terms of years since 2013, t.

Check the BEST answer:

• N=700,000(1.05)t

• N=700,000(1.5)t

• N=700,000(1-0.05)^t

• N=700,000(0.95)^t

An air freshener starts with 30 grams of fluid, and the amount of fluid decreases by 12% per day. Express the amount of grams of freshener, Q, that remains, t, days after it has begun being used.

Check the BEST answer: (HINT: that means simplify what is in the parenthesis)

• Q=30(1+0.12)^t

• Q=30(1-0.12)^t

• Q=30(0.88)^t

• Q=12(1.30)^t

P = 8(1.23)^t

What is the growth rate?

Write as a percent!

Q = 3.1(0.78)^t

What is the initial quantity?