Question 7: What could we conclude from this graph?
There is no obvious relationship between the residuals and the predictor variable.
There is therefore nothing to suggest that a simple straight line is not a good model for these data.
There is also nothing to suggest that the variability of the residuals gets greater or less as height increases. The variability appears to be uniform.
The two outliers can be seen clearly at the top of the graph. These represent two respondents with unusually high reported BMI.
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