Andrew has these marks: English 82%, French 75%, History 78%, Science 80%

a) What mark will Andrew need in math if he wants his mean mark to be each percent?

i) 80% ii) 81% iii) 82%

b) Is it possible for Andrew to get a mean mark of 84% or higher? Justify your answer.

Guest Feb 15, 2017

edited by
Guest
Feb 15, 2017

#1**+5 **

a)

i - In order for Andrew to average 80% in 5 subjects, he would have to score 85% in Math.

ii-...................................................81%.............................................................90% .............

iii-..................................................82%..............................................................95%..............

b) If the maximum mark is 100%, then it is NOT possible for Andrew to get an average of 84%, since he would need a score of 105% in Math, which I assume is not allowed.

Guest Feb 15, 2017

#2**0 **

Here's a (i) .....the other two are worked the same way

Average = 80 ...so.....

[ 82 + 75 + 78 + 80 + ? ] / 5 = 80 multiply by 5

82 + 75 + 78 + 80 + ? = 400

315 + ? = 400

? = 400 - 315 = 85 is the % he needs

b 84 * 5 = 420........he only has 315...so...he needs 105 (%) on the last test.....impossible

CPhill
Feb 15, 2017