Now, lets say that I observe two more people and I see that they also have IQs of 110. So we have three people with IQs of 110. How does the variance of my estimate change from my prior? We can do this in the code by setting:

 
 
 
 
 

The variance should decrease. If we run the code, we can see that the width of the distribution decreases indicating the variance of the estimate also decreased