Exponential functions Quiz-

Which function shows exponential decay?

• $y=12.5\left(1.325\right)^x$

• $y=300\left(1.06\right)^x$

• $y=5000\left(0.98\right)^x$

• $y=1.02^x$

Write an equation to represent the following senario: Supppose $24 has been invested in the year 1662 in an account paying 4.5% interest compounded annually.

Which value represents the growth factor?  $y=10\left(1.036\right)^x$  

• 10

• 1.036

• 36

• none of the above 

Identify the original amount in the exponential function:  $f\left(x\right)=10\left(1.036\right)^x$  

• 10

• 1.036

• 36

• none of the above 

A population of 24,500 people has been increasing at a rate of 1.8% a year. Which function best represents this scenario?

• $y=24,500\left(1.8\right)^x$

• $y=24,500\left(1.018\right)^x$

• $y=1.8\left(24500\right)^x$

• $y=24500\left(0.982\right)^x$

A population of 24,500 people has been increasing at a rate of 1.8% a year. What will be the population in 15 years, if it continues at that rate?

Select all exponential decay funtions.

• $y=0.68^x$

• $y=0.54\left(2\right)^x$

• $y=68\left(\frac{5}{4}\right)^x$

• $y=2\left(\frac{1}{3}\right)^x$

Write a function for: A population of 15,000 decreases 1.2% annually.

A population of 25,000 is decreasing by a rate of 2.1% per year. What is the projected population in 10 years?

• 20,219

• 30,775

• 525,000

• 77,000

Since 1990, the population of Virgina has grown at an average annual rate of about 1%. In 1990, the population was about 6,284,000. Suppose this rate growth continues, predict Virginia's population in the year 2020.

• 4,648,277

• 8,469,883

• 7,667,674