To this point in the lesson, you have learned how to determine the best polynomial regression function to model a set of data. The remainder of this lesson focuses on using the polynomial regression to solve problems.
Graph the data using Steps 1 to 7 as shown in Examples 1 to 4. Place time in L1 and distance in L2. Graph the regression model using Steps 8 to 11 as shown in Examples 1 to 4.
Step 1: Go to the CALCULATE menu; press 2nd, TRACE. Step 2: Select value; press 1. Step 3: Type in the required x-value; press 45. Step 4: Get the corresponding y-value; press ENTER. The distance travelled in 45 minutes is approximately 34.27 kilometres.
Step 1: Input the given y-value; press Y=, down arrow to scroll to Y2, 25. Step 2: Gaph the functions; press GRAPH. Step 3: Go to the CALCULATE menu; press 2nd, TRACE. Step 4: Find the intersection of Y1 and Y2; press 5, ENTER, ENTER, ENTER. Nicola takes approximately 32.65 minutes to drive 25 kilometres. |