Answer:
a. Scatterplot is attached.
b. Positive Correlation
c. Correlation coefficient=0.9219
Step-by-step explanation:
a.
The following procedure will be used to obtain the scatter plot
- Open an Google Sheets file online or excel sheet on your computer.
- In column B and C, enter the Income and Vacation data as provided above.
- Select the data > click on insert CHART.
- Chose Scatter Chart option
A scatter plot visualizing your data should be displayed as attached.
b.
- On your computer, open a spreadsheet in Google Sheets.
- Double-click on your scatter plot.
- At the right, click on Customize tab and then Series.
- Scroll down and check the Trend line box
-From the trend line, your notice that your variables have a positive correlation.
-As the income increases, so does vacation expenditure.
c. The correlation coefficient can be calculated as follows.
- Click on any empty cell in the sheet and enter the formula
- "=CORREL((y-axis range),(x-axis range))"
- ENTER
-From our Google Sheets calculation our variables have a positive correlation and the correlation coefficient is 0.9219
-The correlation coefficient,r can also be calculated manually:
-let x be income, and y be vacation and divide all the values by 100 to make the smaller and easier to manipulate:
[tex]r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2-(\sum x)^2][n\sum y^2-(\sum y)^2}}\\\\\\\sum xy=153914\\\sum x=4485\\\sum y=246\\\sum x^2=2878447\\(\sum x)^2=4485^2=20115225\\(\sum y)^2=246^2=60516\\\sum y^2=8392\\n=8\\\\\#substitute \ and \ solve \ for \ r\\\\=\frac{8\times153914-4485\times 246}{\sqrt{[8\times 2878447-4485^2][8\times 8392-246^2]}}\\\\=0.92186\\\\\approx 0.9219[/tex]
