Use the given data to find the best predicted value of the response variable. Ten pairs of data yield requals0.003 and the regression equation ModifyingAbove y with caret equals2plus3x. ​Also, y overbarequals5.0. What is the best predicted value of y for xequals​2?

Respuesta :

Answer:

[tex]\hat y=3(2) +2=8[/tex]

Step-by-step explanation:

Data given

r=0.003 represent the correlation coefficient

[tex]bar y =5[/tex] represent the sample mean for the y observations

Solution to the problem

We assume that they use least squares in order to find the best regression model. The slope is given by the following formula:

[tex]m=\frac{S_{xy}}{S_{xx}}[/tex]

Where:

[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}[/tex]

[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}[/tex]

And the slope on this case is:

[tex]m=3[/tex]

Nowe we can find the means for x and y like this:

[tex]\bar x= \frac{\sum x_i}{n}=5[/tex]

[tex]\bar y= \frac{\sum y_i}{n}[/tex]

And we can find the intercept using this:

[tex]b=\bar y -m \bar x=5-(3*\bar x)=2[/tex]

So the line would be given by:

[tex]\hat y=3x +2[/tex]

And the best predicted value for x=2 would be:

[tex]\hat y=3(2) +2=8[/tex]