Question

suppose you scored a 99%, 67%, 83%, and 86% on your last four science tests. if your next text counts twice, is it possible to average a 90%? explain your answer.

Answer 1

If you get the maximum grade in the last test, your average grade will still be below 0.9 = 90%, which means that it is not possible to average a 90%.

Explanation:

Average grade:

The average grade is given by the sum of all averages, divided by the number of tests.

In this question:

99%, 67%, 83%, and 86%.

Next test counts twice, which means that in total, there are 6 tests.

Is it possible to average a 90%?

The maximum grade in a test is 100% = 1. I will calculate the average grade you get a 100% on the last test, which is worth 2. So

`M = (0.99+0.67+0.83+0.86+2*1)/(6) = (5.35)/(6) = 0.892`

If you get the maximum grade in the last test, your average grade will still be below 0.9 = 90%, which means that it is not possible to average a 90%.