Exponential Growth and Decay

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x

Is the pictured graph growth, decay, or linear or none?  

• Exponential Growth
• Exponential Decay
• Linear
• None

Is this exponential growth or decay?

• Growth
• Decay

Write an equation that models the following situation:
Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x
• y=6(1+14)^x
• y=6(1.14)^x
• y=6(0.86)^x

Daniel’s Print Shop purchased a new printer for $35,000. Each year it depreciates at a rate of 5%. How much will the printer be worth in 8 years?

• $23,219.72
• $136.72
• $51,710.94
• $16,710.94

A stamp gets more expensive each year.  It increases in value by 60 % each year.  What is the growth FACTOR?

• .6
• 1.06
• 1.6
• .4

Suppose you deposit $3000 in a savings account that pays interest at an annual rate of 4%.  What is the growth factor?

• .96
• 1.4
• 1.04
• $3000

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x
• y = 15(1.35)^x
• y = 15(0.35)^x
• y = 35(1.15)^x

Since January 1980, the population of the city of Brownville has grown according to the mathematical model y=720,500(1.022)^x, where x is the number of years since January 1980. What is the was the population of Brownville in 1980?

• 102.2 people
• 720,500 people
• 1.022 people
• 1022 people

Classify the model as Exponential GROWTH or DECAY.
A=1200(.85)⁶

• Growth
• Decay