The Methacton Education Association and school board have ratified a new contract, ending the threat of a strike. The union had authorized a walkout for October 15, but it was averted the night before when both sides agreed to recommend approval of a compromise worked out with help from a state mediator. The old contract expired on June 30 of last year, and the new one is retroactive to that date. It gives teachers pay raises of a little more than 14 percent over four years. It also boosts the teachers’ share of health insurance premiums to eleven percent in the third year and twelve percent in the fourth year.