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Least-Squares Regression

  1. Oct 8, 2003 #1
    Concrete road pavement gains strength over time as it cures. Highway builders use regression lines to predict the strength after 28 days (when curving is complete) from measurements made after 7 days. Let x be strenth after 7 days (in pounds per square inch) and y the strength after 28 days.

    y-hat = 1389 + .96x

    Draw a graph of this line, with x running from 3000 to 4000 lbs per square inch.


    I don't know how to graph it because the words are confusing me . . . I labed my explanatory (x-axis) as psi from 3000 to 4000 lbs and the response variable (y-axis) as days. How do I graph 1389 (the intercept) on my graph if the y-axis is days?
  2. jcsd
  3. Oct 8, 2003 #2
    I solved it, thanks anyway
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