Name_________________________________________________________
CCSS
N.Q.1
Date __________
Free Throws
A basketball manager records the average amounts of time players spent
practicing free throws each day and the percent of free throws they made during
the season. The results are shown.
1. Make a scatter plot of the data. Let the average amount of time spent
practicing each day be the independent variable x and let the percent of free
throws made during the season be the dependent variable y. Which units
did you use for the independent variable?
2. Make a scatter plot of the data using different units for the independent
variable. Then compare the scatter plots.
3. Write an equation for a line of fit for each scatter plot. Compare the
equations.
4. Is it appropriate to use seconds as the unit of measurement for the
independent variable? Explain.
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Big Ideas Math
Performance Tasks
1
CCSS
N.Q.1
N.Q.1
Common Core State Standard
Use units as a way to understand problems and to guide the solution of
multi-step problems; choose and interpret units consistently in
formulas; choose and interpret the scale and the origin in graphs and
data displays.
CCSS
N.Q.1
Grading Rubric
Answers
Score
1. Student chooses a unit for the independent variable and presents a
2
graph that shows the ordered pairs from the table.
Sample answer: minutes
2. Student chooses a different unit than Exercise 1 for the
independent variable and presents a graph that shows the ordered
pairs from the table; Sample answer: The scale of the x-axis is
different, but the scatter plots are similar and show the same type
of relationship regardless of the units used for the independent
variable.
2
3. Sample answers: y = 0.3 x + 67.5; y = 18 x + 67.5; The y-
intercepts are the same but the slopes are different because of the
scale for the x-axis.
4. Sample answers: no; Numbers would be large and would make it
more difficult to construct the scatter plot and find a line of fit.
3
2
Precision
1
1. Student scales the axes appropriately.
2. Student scales the axes appropriately. Student recognizes that the
scales for the x-axis are different for the scatter plots but the
relationship is the same.
2
3. Student writes equations for the lines of fit and compares them.
2
4. Student recognizes the disadvantages of using seconds as a unit of
measurement for the independent variable.
Total Points
2
Big Ideas Math
Performance Tasks
1
15
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