Answer:
To improve your grade from 80% to 81%, you need to earn an additional 1 percentage point. To calculate the score you would need on a test out of 70 to achieve this improvement, you can set up the following equation:
(Your current total score + Test score) / (Total possible score) = 81%
Plugging in the values:
(80% + Test score) / 70 = 81%
Now, solve for the test score:
0.80 + Test score / 70 = 0.81
Subtract 0.80 from both sides:
Test score / 70 = 0.81 - 0.80 = 0.01
Now, multiply both sides by 70 to isolate the test score:
Test score = 0.01 * 70 = 0.70
So, you would need to score 0.70 or 70% on the test to improve your grade from 80% to 81%.