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Do the freshmen really have the largest backpacks, or is that just high school legend? Delenn was able to weigh a random sample of student backpacks throughout the school year. She also recorded the number of quarters of high school completed by the student who owned the backpack. Using spreadsheet software, Delenn created the following data representations:
First quadrant graph, x axis labeled, quarters of H.S. completed, y axis labeled, Backpack weight (lbs). The ordered pairs from the table are plotted & decreasing line passing approximately through the points (0, comma 14) & (14, comma 6), such that the points, in relation to the line, from left to right are: above, above, above, above, below, below, below, below, below, above, above, below, on, above, below, below.

  1. Interpret the slope of the in the context of this study.

    What are the units associated with the slope? Is the slope positive or negative?

    On average, student backpacks get lbs lighter with each quarter of H.S. completed.

  1. Calculate and interpret -squared in context.

    Square to find -squared.

    _______ % of the variability in ______________ can be explained by a linear relationship with _______________.

  2. What is the residual with the greatest magnitude and what point does it belong to?

    Which point is farthest from the , or which pointis farthest from the -axis on the residual plot?

    The largest residual is 6.2 lbs, relating to a student who has completed quarters of H.S.

  3. Using the model, estimate the weight of a backpack for a student who has completed quarters of high school. Use appropriate precision in your answer.

    Let in the given equation.

  4. Is a linear model the best choice for predicting backpack weight in this study? Support your answer.

    Does the residual plot have random scatter?

Quarters Completed

Backpack Weight (lbs)

A residual graph with the x axis labeled as Quarters of high school completed and y axis labeled as residuals in pounds. The points are scattered above and below the x axis. Your teacher will provide you with a model of the graph.