1. Day 43 – Calculating Correlation Coefficient using Excel

2. Problem
General Scenario: Dr. Truong wants to examine the relation between the amount of television that people watch and how happy they are. Ten adults participate in her study. Each participant records the total number of hours of TV that he or she watches for a particular week. In addition, at the end of the week, each participant completes a questionnaire that measures the person’s overall happiness. The questionnaire scores can range from 0 (extremely unhappy) to 10 (extremely happy). The results from Dr. Truong’s experiment are listed below.

3. Table
Participant Number
Hours of TV Watched
Happiness Score

4. 3 Examples
Copy the information into your Excel Spreadsheet

5. Computing the Mean

6. Computing Mean, or (average in Excel)
Click this
On the Formulas tab, click “More Functions”
Select these cells by dragging it
This should appear
Select “Statistical”, then choose “AVERAGE”
Press “Enter” key twice
This would be your
“mean”
Select the cell where you want to put your mean

7. Computing the Median

8. Computing Median Type in “=median(“ Select the numbers by dragging it
Press “Enter” key
This is your Median
Select the cell where you want to put your median

9. Computing the Mode

10. Computing Mode Type “=mode(“ Select the numbers by dragging it
Press “Enter”
This is your mode
Select the cell where you want to put your mode

11. Computing the Correlation Coefficient

12. Getting the correlation coefficient
Compute the Pearson correlation coefficient between hours of TV watched and happiness (round to two decimal places).
Type in “=CORREL(“
Select your array1
Put a comma “,”
Select your array2
Press “Enter”
There it is, a strong negative correlation coefficient.
Don’t forget to round two decimal places.
Select the cell

13. Let’s Create a Scatter Plot

14. Creating a scatter plot on the data given
Select the cells
On Insert Tab,
click Scatter
Select “Scatter with
only Markers”

15. On Layout Tab, click
“Axis Titles”
Click the primary horizontal
axis title, select “Title Below
Axis.” Type “Hours of TV Watched”
Click the primary vertical
axis title, select “Vertical Title.”
Type “Happiness Score”

16. Drawing the Line of Best Fit

17. Draw the line of best fit
Make sure you
click on the graph
Under the
Layout Tab
Click Tredline,
then chose,
“Linear Tredine”

18. The Line of best Fit