3.10 Effects of New Data ?

summarize_beta_binomial(alpha = 45, beta = 55, y = 30, n = 50)

##       model alpha beta mean      mode         var         sd
## 1     prior    45   55 0.45 0.4489796 0.002450495 0.04950248
## 2 posterior    75   75 0.50 0.5000000 0.001655629 0.04068942

• A comparison illuminates the polling data’s influence on the posterior model. Mainly, after observing the poll in which 30 of 50 people supported Michelle, the expected value of her underlying support $\pi$ nudged up from approximately 45% to 50%.