Answer:
$5.85
Step-by-step explanation:
You know the lines on a number line those can be fractions
Total marks for five tests = 85 * 5 = 425
Total marks in six tests with 90% would be: 90 * 6 = 540
So, the remaining marks will be: 540-425 = 115
Student must earn 115 grade in order to reach other average score of 90%
Hope this helps!