Here's the only way masking could possibly work

Everyone has to wear an N95 mask properly at all times. But even then they're not all that effective as research has proven. But carry on with your vaunted Massachusetts "study" comparing two school districts to 78, which is mathematically unsound. And keep ignoring the experiences of Savannah schools where mandatory masking made no difference, and also the entire state of South Carolina where mandatory masking made no difference, either.