Question

Open excel In one column enter 8 heights for 10 year old boys (inches) and in the second column enter 8 weights for 10 year old boys (pounds). Ten year old boys height ranges from 42 inches to 62 inches while the weight ranges from 60 to 90 pounds. You can make these up as long as they are reasonable if you do not have access to any data. We want to see if there is a correlation. Move your mouse to put a box around the numbers. From the insert menu select scatter or the chart that says scatter and then select the chart at the top left on the dropdown Click on one of the points Select Add Trendline The default radio button is linear, keep it checked Check display equation on chart and click on the display r-squared value The equation is your least squares line On the least squares line the slope is in front of the x value. Also, you can look at the slope of the scatter plot to see if the slope is positive. This will let you know whether to make the r value positive or negative when you take the square root of r^2. If the r^2 value is say .0382 then you will click on an excel cell and type =.0382^.5 Note the ^ key is above the 6 key This will be your r value and you will make it negative if your slope is negative otherwise leave it positive. If you have a different version of excel then you may want to search to see how to form a trendline. These instructions work with Office 365 and Office 2010. Then follow these instructions: Attach your scatter plot if possible. What did you get for your regression line? What was your r value? What did this tell you? What would be a scenario where you might need to use this application? Explain in a minimum of 250 words

Answer 1

The problem is solved in excel in following steps,

Step 1: Data values:

	Height	Weight
1	62	83
2	62	87
3	47	74
4	59	71
5	62	90
6	54	68
7	51	68
8	57	87

Step 2: Scatter plot

Select the data values then INSERT> Recommended Charts> X Y Scatter > OK.

The Chart is obtained. The screenshot is shown below,

Step 3: To add Trend line, linear equation and R-square value in plot.

Click on Add Chart element> Trendline > More options>OK. The screenshot is shown below,

Now tick box for Display Equation on Chart and Display R-squared value on Chart. The screenshot is shown below,

Step 4: Correlation

Step 5: Conclusion:

From the scatter plot and positive correlation coefficient, we can say that the weight of 10 year old boys increases as height increases.