Instructions
For this discussion post, you can choose one of the two discussion questions.
Choose one of the questions from the team exercises or “Critical Thinking and Values for Effective Problem Solving” in Chapter 7 from the textbook, “R and Statdisk: A companion for Introductory Statistics”. If you choose a team question, you may work with up to 3 total classmates to compose the response, although you may also complete it alone.
or
Create an example of using Excel to demonstrate scatter plots and regression lines to understand relationships between quantities.
We will need to find 10 data points. Be creative!
A good example would be for instance measuring temperature over time. You can go online and find the temperature in your city over a period of 10 days. This could be recent temperature, or winter temperature. The x values will be 1 – 10 as these will be 10 days you will be investigate in order. The y values will be the temperature that are given in your data source/website. Make sure you provide a screen shot of where you found the information from. It could be other things as well. Just make sure it is clear what you are studying with your example.
Here are the steps you can follow to complete this example:
Open an excel worksheet.
List 10 x values in cells a1 to a10
List 10 y values in cells b1 to b10
Use the instructions to find the r value, scatter plot and regression line. Enter the x and y values.
• Highlight the data.
• From the insert menu, select scatter (select top left chart).
• Now select the data series by right-mouse clicking on the top right point.
• This will highlight all the data points.
• Select “Format Trendline”
• The default radio button is linear, Keep it checked.
• Check Display Equation on chart and the R-squared value and click closed.
• The equation is your linear regression equation.
• The R-squared value is the coefficient of determination.
• To find the R value take the square root of the r-squared value or (r-squared value) ^ .5 since .5 is to the ½ power.
Then if the slope of the line is positive, r is positive, and if the slope of the line is negative r is negative. On the linear regression line, the slope is in front of the x value. Also, you can look at the slope of the line on the scatter plot.
Take a screen shot and post it in your discussion post. Is there a linear relationship? Explain your answer.
Please remember that you need to post your initial response by Thursday night at midnight. Then please respond to at least two of your classmates by Sunday night at midnight.
You will earn 6 points for a well thought-out initial response to the discussion question and 4 points for well thought out responses to your classmates.