Exponential Growth or Decay Solving

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

• 0 people

• It doesn't say

• I don't know

• 6191

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

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(0.7)^x

• y=30(5000)^x

• y=5000(1.3)^x

• y=5000x^x

The exponential graph:
Y=(⅕)^{X
Would be...}

• Exponential Decay

• Exponential Growth

• Linear

You buy a new computer for $2100. The computer decreases by 50% annually. How much is it worth after 2 years.

• 225

• 325

• 425

• 525

Identify the common ratio (multiplier) of the function f(x)=2(4)^x.

• 2

• 4

• (2)^x

• 8

Does the following equation show growth or decay?
y=10,000*(0.76)^x

• Growth 

• Decay

Find the time required for an investment of $1000 to grow to $5000 at an interest rate of 8% per year compounded monthly. (round to nearest year)

• 1 year

• 242 years

• 20 years

• 13 years

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