mean score of 90% for his tests. so far he has 85 78 98 93 90 percent whatsthelowest scorethesixthtestcanhave?

Question

Real questions is...
Arthur wants to have a mean score of 90% for his 6 reading tests. So far his scores have been 85%, 78%, 98%,93% and 90%. What is the lowest score on the sixth test he could get and still get his 90 average?

Answer 1

Solve for x, where x = score on 6th test
(95 +78 +98 +93 +90 +x)/6 = 90

Answer 2

To get a 90 average his 6 tests must total 6(90) =540

Add up his test (85+78+98+93+90) = 444

and subtract from 540 = 96

Answer 3

85 + 78 + 98 + 93 + 90 = 444
( 444+ x ) / 6 = 90
444 + x = 90 ( 6 ) = 540
x = 540 - 444 = 96

Check
(85 + 78 + 98 + 93 + 90 + 96) / 6 = 90

Answer 4

Well, for 6 tests, to find a minimum mean (or average) of 90, you should multiply 90 by 6.

90 x 6 = 540

To find out how many more points he needs to achieve that total, you must subtract the total of his previous tests from 540.

540 - (85+78+98+93+90)
540 - 444 = 96

So, looks like he will have to study very hard, because he will need at least a 96% on his last test to achieve a minimum of 90% for his test average.

Answer 5

well, think about how a mean schore is calculated

add all the scores and divide by the number of scores

so, if x is the score of his sixth test

then (85+78+98+93+90+x)/6=90 will allow you to calculate the value of x that will give a mean of exactly 90

any score lower than that will give a final average lower than 90

so the algebra reduces quickly to

444+x=540
or
x=96

Answer 6

To get an average of 90%, the sum of the scores must be 90(the desired average)x6(the number of tests) or 540. Subtracting the scores he's already received, he will need a score of 96 or higher.

Answer 7

90:Ice Cube Amerikkka's Most Wanted 91: A Tribe Called Quest A low End Theory 92. Pete Rock and CL Smooth Mecca and the Soul Brother 93: Black Moon Entra da Stage 94: NaS Illmatic 95: GZA Liquid Swords 96: Ghost face Killah: Ironman 97: wU tANG fOREVER 98. Mos Def and Talib Kweli: Black Star 99: Dr. Dre. 2001

Answer 8

He needs 540 points in total to achieve that average (6 times 90). You should be able to figure it out from here.

Answer 9

96