A3-A2-Linear Regression

YOU WILL BE SUBMITTING A WORD DOCUMENT WITH 6 ANSWERS AND A GRAPH.

Type your answers in a word document.  Copy and paste the scatter plot to the word document.  Save using your last name and first name.

Submit the answers to your questions and the attached file of your scatterplot in the Dropbox for Module 3.

Step 1:  Go to the Module 3 Assignment 2 page and click on the blue link to open the Excel Spreadsheet            containing the data to use.

Step 2:  Save the spreadsheet on the computer using your Last Name_First Name

Step 3:  Highlight all of column A and B – not including the labels in row 1.

Step 4:  With everything highlighted, go to the top of the page and click on the INSERT tab.

Step 5:  Look across the top of the page and in the “Charts” section – click the “Scatter” graph.  It looks like a bunch of dots.  This causes a drop down menu to open.  At this point, click the first option in     the list.

Step 6:  Now there is a chart on the page showing the scatter plot of the information you entered. 

Question 1:  What do the numbers on the bottom of the chart represent?  _______________________

                        Hint:  Look at the labels for the data!

Question 2:  What do the numbers on the vertical axis represent?  _______________________________

                        Hint:  Look at the labels!

Step 7:  Next you are going to add a “Trendline” in the chart.  Pick any dot on the scatterplot.  Right click on that dot.  It   will cause a dropdown menu.  At this point, select “Add a Trendline”.

Step 8:  Make sure that “Linear” is selected.  Also, at the bottom of this menu, check on “Display Equation on Chart” and             “Display r-squared value on chart”.

Step 9:  Close this page.  This will bring you back to your excel page with your chart.

Step 10:  This line shows the relationship between the two variables.  If the line goes up as you go right, it is a positive                   correlation.  If the line goes down as you go right, it is a negative correlation.  The “r²” value shows you how                     strong the relationship is.  The closer the value is to 1 – the stronger the relationship.

Question 3:  Is your relationship positive or negative?

Question 4:  How strong do you feel the relationship is and why?

Question 5:  Write the correlation (relationship) in a sentence form using the names of the data.

Question 6:  Are there any other variables that could be contributing to the results?