Question

3.) Given are five observations collected in a regression study on two variables.

	2	6	9	13	20
	7	18	9	26	23

1. Develop a scatter diagram for these data.
2. Develop the estimated regression equation for these data.
3. Use the estimated regression equation to predict the value of y when x=6

17.) The data from exercise 3 follow.

	2	6	9	13	20
	7	18	9	26	23

The estimated regression equation for these data is . What percentage of the total sum of squares can be accounted for by the estimated regression equation? What is the value of the sample correlation coefficient?

25.) The data from exercise 3 follow.

	2	6	9	13	20
	7	18	9	26	23

1. What is the value of the standard error of the estimate?
2. Use the F test to test for a significant relationship. Use alpha = .05. What is your conclusion?

Answer 1

Q 3 )

A)

We have to find scatter plot

By using the minitab we can find out the scatter plot as

First enter all data in minitab worksheet then

Click on Graphs--------> Scatterplot ------->Click on simple ------> OK
we get the output as follows

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B) The least square regression is

Where, y = Dependent variable

x = Independent variable

a = Intercept and

b = Slope

By using the excel we can calculate the intercept and slope as

Put all the data in excel worksheet then

Excel command is

For Intercept =INTERCEPT(Select all the data of y's,Select all the data of x's)

For Slope    =SLOPE(Select all the data of y's,Select all the data of x's)

we get

Intercept = 7.6 and Slope = 0.9

we get the least square regression equation is

.......................(Answer)

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C) we want to the estimated regression equation to predict the value of y when x=6

By using the least square regression is

Put x=6

we get

..................(Answer)

The predicted value of y when x = 6 is 13 ...................(Answer)

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