"anchor" href="#exercise-13-1-brain-size-body-size-relationships"></a>
</h2>
<p><em>Does brain size scale as the 2/3 power of body size?</em></p>
<p><em>How should we analyse the data to answer this research
question?</em></p>
<p>We are primarily interested in the slope coefficient, and do not have
a predictor and a response, rather we have two response variables. So we
want to avoid regression to the mean and should look at this as a
multivariate problem, and use principal components analysis (or related
m