Are homes in good school districts more expensive?

Here is the graph of home prices and school rank for 125 towns in Massachusetts. Home price is average sold price of all single family homes YTD in that town, taken from MLS. School rank is Boston magazines school ranking for 2017, inverted so the data would make more sense. For example, Dover Sherborn is ranked #1 but has a score of 125 whereas Chelsea is ranked #125 but has a score of 1. 

 

There is a strong correlation (correlation .64) between home price and school rank across Massachusetts. However, if you look at any 20 town segment, for example the top 20 ranked schools there is a very weak, almost no correlation between home price and school rank. 

 

So your conclusion from the data might be "yes, in general the more expensive homes are located in a higher ranking school districts", or "lower priced homes are located in lower ranked school districts" but you can't conclude that it makes more sense to buy in Wellesley where the homes cost $1.5m versus Sherborn where homes cost $859k to get a better school system because the data doesn't show that, it shows the opposite in fact for those two towns.