Simon must maintain an average grade of 80% or better in his math class to be eligible to play sports. His math grades so far are: 80%, 84%, 76%, 77%. At this point, his grades make him ineligible to play. What is the lowest he score on his next grade to bring his average score up to an 80%. Part A: Write an inequality to represent the average of the five grades as greater than or equal to 80%. Part B: Use the inequality from Part A to prove what his lowest score could be on the 5th test.