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.(adsbygoogle = window.adsbygoogle || []).push({});

y-hat = 1389 + .96x

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

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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?

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# Least-Squares Regression

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