Answer:
81
Step-by-step explanation:
Given total number of tests are 5
The grades earned by the students in the tests are 84 , 75 , 97 , 89
let the grade earned by the student in the fifth test be x.
Average=[tex]\frac{84+75+97+89+x}{5}[/tex]
The condition recquired is Average≥85
[tex]\frac{84+75+97+89+x}{5}[/tex]≥85
[tex]\frac{344+x}{5}[/tex]≥85
[tex]x+344≥425[/tex]
x≥81.
The least grade the student can earn in the last test so that average is not less than 85 is 81
