# Correlation Home Work Review

#### mcafeep

##### New Member
Attached is my assignement for this week can you look it over and tell me what you think.

Thanks

#### JohnM

##### TS Contributor
Just a few observations:

- adjust/shrink the x-axis range on your graph so that the dots take up more of the area

- use the Excel chart feature "Add a Trend Line" so that you can see the regression line, as well as r^2 and the equation on the chart

- the question asks whether the relationship is linear, non-linear, or nothing, so in addition to the linear, so you'll need to check other types of trend lines to see if it "improves" the fit (increases r^2)

- you may want to add commentary that talks about the regression equation (i.e., for every $xxx increase in retail sales, we'll see an approx$xxx increase in online sales, etc.)

- your last comment about "causation" is incorrect --> since this is an observational study and not a controlled experiment, you cannot make any statements about cause-and-effect, only that there is "an apparent relationship or association" between the variables

#### mcafeep

##### New Member
One More Question

- you may want to add commentary that talks about the regression equation (i.e., for every $xxx increase in retail sales, we'll see an approx$xxx increase in online sales, etc.)

I know how to do regression in excel but what am I looking for I dont see it