Exercise

# Assumptions II

Let's pretend that we obtained our data randomly from independent participants. That means we have addressed the assumption of **independent errors**.

Another assumption that we can tell definitively is **sufficient observations**. We have ten observations and two predictors - we know already that this is not enough!

One good thing about having only ten observations is that it is easy to manually check for regression outliers. We do this by looking at the standardized residuals. We can find the standardized residuals by *dividing the values of the residuals by the standard deviation of the residuals*. Standardized residuals greater than 3 or less than -3 are likely outliers.

Instructions

**100 XP**

- Your residuals are in your script as
`resmod`

, and you can find the standard deviation of the residuals using the function`sd()`

, which takes the object containing your residuals between brackets. - In your script, add a line of code to print the standardised resdiuals.
- Inspect the output and see if you can see any standardized outliers over 3, or under -3.