standard_description: Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions. (Students able to multiply fractions in general can develop strategies to divide fractions in general, by reasoning about the relationship between multiplication and division. But division of a fraction by a fraction is not a requirement at this grade.)
problem_activity: Problem 1
The scatterplot below displays the elevation and mean number of clear days per year of  U.S. cities. Two lines are shown on the scatterplot. Which represents the least squares line? Explain your choice.
[IMG]
Problem 2
Below is a scatter plot of foal birth weight and mare’s weight.
[IMG]
The equation of the least squares line for the data is
$${y=-19.6+0.248x}$$
, where
$$x$$
= mare’s weight (in kg) and
$$y$$
= foal’s birth weight (in kg).  What foal birth weight would you predict for a mare that weighs 520 kg?
How would you interpret the value of the slope in the least squares line?


aligns: no