Use the graphing calculator to calculate the quadratic regression equation of the following data:
X- 1,2,7,8,12,13,18,19,20,24,25
Y- 3.9,3.5,3.1,3.1, 3.8, 3.9, 5.0, 5.3, 5.4,6.3,6.4
Use your calculator to determine when y=4.2
To find the quadratic regression equation of the data given, you will first need to enter the data into a graphing calculator.
1. Enter the X values into the list L1: 1, 2, 7, 8, 12, 13, 18, 19, 20, 24, 25
2. Enter the Y values into the list L2: 3.9, 3.5, 3.1, 3.1, 3.8, 3.9, 5.0, 5.3, 5.4, 6.3, 6.4
Next, perform a quadratic regression analysis on the data:
1. Press the "STAT" key.
2. Select "CALC" and then select "QuadReg" (option 5).
3. Enter the lists L1 and L2 for X and Y.
4. Press "ENTER" to calculate the regression equation.
The resulting quadratic regression equation should be something like:
Y = ax^2 + bx + c
Using that equation, you can substitute y = 4.2 and solve for x to determine when y = 4.2.