Hello Ayo- I think that's great that you're looking into the MCAS scores of potential public schools for your child/ children. Qualities of schools and teachers and school programs and services can vary greatly within a county. I don't know off the top of my head, but my guess is there are 25-35 middle schools in Worcester County. Many of them are in towns that are quite different from Worcester. It might be tough to compare.
You might consider one of the neighboring towns near Worcester that may have a school system that aligns more with what you're looking for. There are still some great real estate deals in most of those towns.
Feel free to contact if you need any further help. Thanks, and good luck,