Fitting Exponentials and Polynomials to DataLinear RegressionProblem … Which Regression?Viewing the Data PointsWhich Regression?Try Different RegressionsSlide 7Slide 8Which is Best?Other Technology ToolsSlide 11AssignmentFitting Exponentials and Polynomials to DataLesson 11.7Linear Regression•Used in section 1.6 to find equation for a line of best fit•Used in section 4.4 to find equations of logarithmic models•Other types of regression are availableProblem … Which Regression?•Not always obvious which type of regression to use•Consider the lobster catch (in millions of lbs.) in the last 30 some yearsEnter into Data MatrixYear1970 1975 1980 1985 1990 1995 2000t5 10 15 20 25 30 35Lobster17 19 22 20 27 36 56Viewing the Data Points•Specify the plot F2, X's from C1, Y's from C2•View thegraphCheck Y= screen, use Zoom-DataWhich Regression?•The graph could suggest different modeling functionsTo find a modeling function which includes the third point makes us think of a polynomial functionTo let that point be off the modeling line, it could be a power function or an exponentialTry Different Regressions•Try for a quadratic function•Try for powerfunctionTry Different Regressions•Try for 4th degreepolynomialTry Different Regressions•What about exponentialregression?Which is Best?•IssuesWhich best fits data?Which gives best predictions for years of given data?Which gives best predictions for future?Might there be one that gives us an idea of what was done in the past (where we have no records)?Other Technology Tools•Excel will also do regression•Plot data as (x,y) ordered pairs•Right click on data seriesChoose Add Trend LineOther Technology Tools•Use dialog box to specify regressionLobster Catch01020304050600 10 20 30 40Years since 1970Millions of Pounds o f LobsterLobster Catch01020304050600 10 20 30 40Years since 1970Millions of Pounds o f LobsterTry OthersTry OthersAssignment•Lesson 11.7•Page 477•Exercises 5, 13, 15, 17,
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