statisticalrethinkin..

162 5. MULTIVARIATE LINEAR MODELSfemales, 7.3 cm. So to compute the average male height, you just add these two estimates:135 + 7.3 = 142.3.at’s good enough for the posterior mean of average male height, but you’ll also needto consider the width of the posterior distribution. And because the parameters α and β mare correlated with one another, you can’t just add together the boundaries in the precisoutput and get correct boundaries for their sum. 66 But as usual, the most accessible way toderive a percentile interval for average male height is just to sample from the posterior. enyou can just add samples of a and bm together to get the posterior distribution of their sum.Here’s all it takes:R code5.42post