1. Lesson 7

1.4. Discover

Mathematics 30-2 Module 7

Module 7: Exponents and Logarithms

 

Discover

 

Try This 1

 

This photo shows a man in a wheelchair reading a newspaper and holding a coffee cup.

George Doyle/Stockbyte/Thinkstock

Each morning a teacher reads the newspaper. He does this with a nice fresh cup of coffee. Many mornings, however, he becomes so focused on his newspaper that the coffee becomes cold and unpleasant to drink.

 

The following data shows the temperature of the cup of coffee as it sits cooling.

 

Time (in min) Temperature (°C)
0 90
5 71
10 52
15 34
20 30
25 27
30 25
  1. Use your graphing calculator to plot the data.
  2. Is the temperature increasing or decreasing?
  3. What is the shape of your scatter plot? What kind of model do you expect to use with this data?
  4. Use your calculator to find a regression equation.
  5. Graph the regression equation on the same graph as the scatter plot.
  6. What is an appropriate domain and range for this situation?
If you have difficulty determining the regression equation, refer to your calculator manual or contact your teacher.
If you have difficulty creating a scatter plot, refer to your calculator manual or contact your teacher.