Bayes 9b: finish the calculation

Just to finish up from last time, we found that Arnie's posterior distribution was Normal(31.83,1.16²). We calculate the Bayesian credible interval using values from Student's t table with df = 4. From wikipedia:

97.5% for df = 4 is 2.776

Compare this to the standard value of 1.96. There is a 95% probability that the true mean lies in the interval

31.83 -/+ 2.776 * 1.16 = 31.83 -/+ 3.22 = 28.61, 35.05