For the third marking period, Joey was reviewing his 7 test scores. On his report card, he received a grade of a 90. While reviewing his scores, he realized that he was missing one. He had the following test scores: 85, 90, 85, 95, 85, and 95. What is Joey's missing test score? Provide mathematical proof and reasoning for how you found the missing test score. 20 point question and marking brainliest