+0  
 
0
150
4
avatar+708 

Use a graphing calculator or other technology to answer the question.

Which quadratic regression equation best fits the data set?

 

yˆ=1568.065x^2+115.265x+2.608

yˆ=2.608x^2−115.265x+1568.065

​ yˆ=1568.065x^2−115.265x+2.608 ​

​ yˆ=2.608x^2+115.265x+1568.065 ​

x             y

15       423

17        398

19        308

20        255

21      297

25      365

29     401

 

i think its B

 Feb 7, 2019
edited by jjennylove  Feb 7, 2019
edited by jjennylove  Feb 7, 2019
 #1
avatar+98129 
+2

I like this website for this : https://keisan.casio.com/exec/system/14059932254941

 

However.....you have to be careful of the output form...

 

They give it as  A  + Bx   + Cx^2

 

But.....our  desired form is    Cx^2 + Bx + A

 

The correct equation is

 

y = 2.608x^2 -115.264 + 1568.065

 

 

cool cool cool

 Feb 7, 2019
 #2
avatar+708 
+1

how do you know wheter to add or subtract it ?

jjennylove  Feb 7, 2019
 #3
avatar+98129 
+2

Look at the output

 

 

Their form is A + Bx + CX^2

 

But...our form  is  just the rearrangement of this as :      Cx^2 + Bx + A

 

So

 

C = 2.608

B = -115.264

A = 1568.065

 

So  we just plug these in and get

 

y = 2.608x^2 -115.264 + 1568.065

 

Does that make sense, jenny???

 

 

cool cool cool

 Feb 7, 2019
 #4
avatar+708 
+1

Yes It does thank you . I will take a screenshot of this.

jjennylove  Feb 7, 2019

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