Kyle has an average of 88 on 4 tests. What must he get on his fifth test to have an average of 90.
can you show me how you got there too.
2007-03-18 13:13:49 · 18 answers · asked by Anonymous in Education & Reference ➔ Homework Help
(88*4+x)/5=90
2007-03-18 13:15:53 · answer #1 · answered by imacowboygirl 3 · 1⤊ 0⤋
98. The technical way to do it is the way the first poster did, as you are translating the problem into the algebraic form.
I just figured that he lost a cumulative 8 points from his goal. (2 points from each of the four tests.) Therefore, he would need 8 points higher than his goal in order to make up for the ones he lost.
Edit - an analysis on the algebraic way:
4 * 88 is what he has scored so far: four groups of 88.
x is the variable, what you don't know.
Dividing by 5 will get you the average of 5 tests.
90 is the target, so it gets a side of the equation to itself.
Therefore:
((4*88) + x) / 5 = 90
(352 + x) / 5 = 90
(352 + x) = 450
x = 450 - 352
x = 98
2007-03-18 20:16:01 · answer #2 · answered by Bobby S 4 · 1⤊ 1⤋
You have 5 tests so you must add up the scores of all 5 of them and divide by 5.
You also know that to get the 88 you divided a number by 4. We need to know that number. N/4 =88; n = 352
Let S be the score of the fifth test
then (352 + S)/5 = 90
Multiplly by 5
352 + S = 450
Subtract 352
S = 98
You must get a 98 on the fifth test to average 90.
2007-03-18 20:22:15 · answer #3 · answered by lizzie 3 · 0⤊ 0⤋
each of the 4 test is worth 100 points each.
so the 4 test would be a total of 400 points
So you take 88*4=352.
So Kyle got 352/400=88%average
A fifth test would round the total of points up to 500
lol well i am not sure how you get the next part but he would have to get 98 out of 100 on the next test to recieve 90%
I got that by taking 352+98=450
450/500=90% average on his test score
hope that helps!!
2007-03-18 20:28:32 · answer #4 · answered by justinsbabygurl21406 2 · 0⤊ 1⤋
(x + 88 * 4) / 5 = 90
Solve for x
(x + 352) / 5 = 90
x + 352 = 90 * 5
x + 352 = 450
x = 450 - 352
x = 98
So Kyle would need to get a 98 on the fifth test.
Please note that in esoterik's answer below, the equation is written incorrectly. (Remember, division and multiplication take precedence over addition and subtraction!) If you solved that equation correctly, you would get the wrong answer:
4(88) + x / 5 = 90
352 + x/5 = 90
x/5 = 90 - 352 = -262
x = -1310
If you wrote the equation that way in a homework problem and solved it as esoterik did, your teacher would mark it wrong for two reasons: 1) the original equation was wrong, and 2) even though you gave the wrong equation, you solved IT incorrectly.
2007-03-18 20:17:22 · answer #5 · answered by greymatter 6 · 2⤊ 0⤋
the answer is 98. ok you add 88 up four times which gives you 352. the in order for an average of five tests to be 90 you have to divide the outcome of 88x4 + ? by 5 right? well the # you have to divide by five is 450. so 450 divided by 5 is 90. in order for you to get 98 you have to see the difference of 450- 352. did that help?
2007-03-18 20:47:25 · answer #6 · answered by Cassie 2 · 0⤊ 1⤋
(88 + 88 + 88 + 88 + X) /5 = 90
88 + 88 + 88 + 88 + X = 450
X = 450 - 352
X=98
2007-03-18 20:23:09 · answer #7 · answered by jhfromuth 2 · 0⤊ 0⤋
88*4+x=90
2007-03-18 20:16:51 · answer #8 · answered by North Cali Girl 1 · 1⤊ 2⤋
4(88) + x / 5 = 90
Find x... This is essentially the problem. So let's solve for x.
4*88 + x = 450
x = 450 - 388
x = 98
A 98!!!!!!!! OOHOLY MOLY
2007-03-18 20:17:25 · answer #9 · answered by F1reflyfan 4 · 3⤊ 1⤋
he'd need a 98
4*88 + x = 450
x = 450 - 388
x = 98
2007-03-18 20:17:46 · answer #10 · answered by Anonymous · 0⤊ 3⤋