Concept Byte: Performing Regressions

Use With Lesson 9-7

TECHNOLOGY

You can use a graphing calculator to perform quadratic regressions and exponential regressions.

Activity

Use a graphing calculator to find a model for the given data.

• Step 1

  
  Image Long Description

  Enter the data into two lists. Enter the x-values in L1 and the y-values in L2.

• Step 2

  

  Make a scatter plot of the data. Press zoom 9 begin box , zoom , end box , 9  to graph. The graph appears to be quadratic.

• Step 3

  

  Perform the regression. Press stat . begin box , stat , end box , .  Select CALC and QUADREG to find the model.

The equation y = 1 . 39 x 2 − 4.14 x + 4.07 y equals 1 . , 39 x squared , minus , 4.14 , x plus , 4.07  models the data. Check the equation by graphing it and the ordered pairs from the table in the same coordinate plane.

To perform an exponential regression, press stat . begin box , stat , end box , .  Select CALC and EXPREG to find the model.

Exercises

Use a graphing calculator to find a model for each set of data.

1. x	y
   − 1 negative 1	4.3
   0	5.1
   1	4.3
   2	2.2
   3	1.3

2. x	y
   − 1 negative 1	12.75
   0	2.83
   1	0.64
   2	0.12
   3	0.04

3. x	y
   − 1 negative 1	0.1
   0	1.2
   1	11.8
   2	115.3
   3	1129.4

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