Unit 6 - Lesson 8 - Grade 8: Illustrative Mathematics

What does the rate of change of the function tell you about the association between stride length and speed?

Is there an association between the weight of an animal’s body and the weight of the animal’s brain?

Are there any outliers?

After removing the outliers, does there appear to be an association between body weight and brain weight? Describe the association in a sentence.

Using a piece of pasta and a straightedge, fit a line to your scatter plot, and estimate its slope. What does this slope mean in the context of brain and body weight?

Does the fitted line help you identify more outliers?

Sometimes a person’s arm span is the same as their height. Is this true for anyone in the class?

Make a scatter plot for the arm span and height data, and describe any association.

Is the line y = x a good fit for the data? If so, explain why. If not, find the equation of a line that fits the data better.

Examine the scatter plot. Which person in your class has the largest ratio between their arm span and their height? Explain or show your reasoning.