Exponential Regression Growth and Decay

A chemist has a 100-gram sample of a radioactive material.  He records the amount of radioactive material every week for 6 weeks and obtains the following data: Find the exponential model of the function. What is the rate of decay?

• 99%

• 100%

• 12%

• 88%

The amount of ants in a colony, f, that is decaying can be modeled by                      f(x) = 800(.87)^x, where x is the number of days since the decay started. By what percentage is the colony decaying?

• 87%

• 13%

• 800%

• 8.7%

Describe the association of the scatter plot.

• Linear

• Exponential; Growth

• Exponential; Decay

• Linear; negative association

Greenville is having a blizzard. It has already snowed 1 inch and the total will double each hour. Write an equation for the total inch of snow in x hour. Use exponential regression.

• y=1(2)^x

• y=1(1/2)^x

• y=2(1/2)^x

• y=2(2)^x

A chemist has a 100-gram sample of a radioactive material.  He records the amount of radioactive material every week for 6 weeks and obtains the following data: How much is left after 12 weeks?

• 15

• 21

• 17

• 19

Use the exponential regression to find an equation that fits the​ data, where x is the years since 1990. How many subscribers will there be in 2015

• 1577.58

• 7.06

• 39.67

• 224.23

After 9 days, approximately how many grams of this substance will exist?

• about 64244

• about 173602

• about 23774

• about 469111

Which of the following is the exponential regression equation for this data?

• Y = 8.16(2.7)^X

• Y = 81.6(2.7)^X

• Y = 8.16(.27)^X

• Y = 8.16(27)^X

A chemist has a 100-gram sample of a radioactive material. He records the amount of radioactive material every week for 6 weeks and obtains the following data. Determine the exponential regression that best models these data.

• y = 100(8.7)^x

• y = 100(1.87)^x

• y = 100(.87)^x

• y = 100(.13)^x