Question

To get a final grade of B, a student must have an average mark on five tests that is greater than or equal to 80 and less than 90.

If Lisa's grades on the first four tests were 97, 93, 78 and $7, solve for the range of grades x that she could score on the fifth test that would result in her getting a final grade of B.

Give your answer as an inequality.

Answer 1

SHE IS RIGHT WHAT SHE SAID IS RIGHT I HOPE YOU GET AT A

Answer 2

46 <= grade < 96 First, let's write the equation for the lower limit that the student must get for a B. (x + 92 + 82 + 88 + 92)/5 = 80 Multiply both sides by 5 giving x + 92 + 82 + 88 + 92 = 400 Subtract 92, 82, 88, 92 from both sides x = 400 - 92 - 82 - 88 - 92 = 46 So the student has to get 46 or higher on the test to make a B. Now let's compute the upper limit (x + 92 + 82 + 88 + 92)/5 < 90 Multiply both sides by 5 (x + 92 + 82 + 88 + 92) < 450 Subtract 92, 82, 88, 92 from both sides x < 450 - 92 - 82 - 88 - 92 ) = 96 So the student has to get a grade of less than 96 to get a B.