To get a B in a course, you must have an average of at least 80 points for 4 tests of 100 points each. For the first 3 tests, your scores were 79, 83, and 81.

What must you score on the 4th test to earn a 80% average for the course?

You must score 77 on the 4th test to earn a 80% average for the course

Step-by-step explanation:

Let the score on the 4th test be x

Then;

(79 + 83 + 81 + x)/4 = 80

(243 + x)/4 = 80

243 + x = 80(4)

243 + x = 320

x = 320-243

x = 77

5/6

step-by-step explanation:

if i remember correctly with perpendicular stuff you just take away the negative