Review of Exponential Functions

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What percent did the population increase each year?

• 4%

• It doesn't say

• I don't know

• 400%

You have inherited land that was purchased for $30,000 in 1960. The value of the land increased by approximately 5% per year. What is the approximate value of the land in the year 2011?

• $344,022

• $31,500

• $15,000

• $28,500

You drink a beverage with 120 mg of caffeine. Each hour, the caffeine in your system decreases by about 12%. How long until you have 10mg of caffeine?

• 19 to 20 hours

• 10 to 20 hours

• 15 to 16 hours

• 5 to 6 hours

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

• Exponential Growth

• Exponential Decay

• Linear

• None

What is the y-intercept of the function?

• 2

• 3

• 1

• -2

Identify the y-intercept (initial value) in the function f(x)=13(.27)^x

• (.27)^x
• .27
• 13
• 3.51

You invest $400 for 5 years and the interest rate is 4.29% each year.

• y=400(1 - 0.0429)⁵

• y=400(1+.0429)⁵

• y=400(1+ 4.29)⁵

• y=400e^0.049*5

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation?

• y=8(15,000)^x

• y=15,000(1 + .08)^x

• y=15,000(1 - .08)^x

• y=15,000(0.08)^x

Is this exponential growth or decay?

• Growth

• Decay

What is the y -intercept of  y=3(4)^x?

• 1

• 0

• 4

• 3