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.

(a)

(b)83%

Step-by-step explanation:

His math grades so far are: 80%, 84%, 76%, 77%.

Let the lowest score required to bring his average score up to an 80% =x

(A)Average of the five scores

=

=

If the average of the five grades as greater than or equal to 80%.

Then:

(b) To find what his lowest score should be, we solve the inequality derived in part A.

Cross Multiplying

The lowest score he requires is 83%.

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3