### Home > CCA2 > Chapter B > Lesson B.1.1 > ProblemB-16

B-16.

Eeeeew! Hannah’s volleyball team left their egg salad sandwiches sitting in their lockers over the weekend. When they got back on Monday they were moldy. “Perfect!” said Hannah. “I can use these sandwiches for my biology project. I’ll study how quickly mold grows.”

Using a transparent grid, Hannah estimated that about $12\%$ of the surface of one sandwich had mold on it. She threw the sandwich out. For the rest of the week, Hannah came back when she had time. Each time she measured somebody else’s sandwich and threw it out. She collected the following data: .

Day 1
(Monday)

Day 2
(Tuesday)

Day 2
(Tuesday)

Day 4
(Thursday)

Day 4
(Thursday)

Day 4
(Thursday)

Day 5
(Friday)

$12\%$

$15\%$

$13\%$

$26\%$

$27\%$

$24\%$

$38\%$

1. Create a scatterplot and sketch it. Is a linear model reasonable?

After drawing your scatterplot, look back at the Math Notes box in Lesson 1.1.2 to help you determine if a linear model is the most reasonable option.

2. Based on the story, what kind of equation do you think will best fit the situation?

Look at the Math Notes box in Lesson 1.1.2 again for help with this question.

Exponential growth fits this situation best.

Use the eTool below to create a scatterplot.
Click on the link at right for the full eTool version: CCA2 B-16 HW eTool