wtf this question made my heard hurts

[IWantH2O]

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kaplans explanation sucks.. so can anybody explain this better to me

the scores on a certain exam were 60, 75, 100, 70 and x. if the median score was 5 points lower than the avage score on the exam, which of the following could be x?
a-70
b-75
c-80
d-90
e-95

 

[doc3232]

kaplans explanation sucks.. so can anybody explain this better to me

the scores on a certain exam were 60, 75, 100, 70 and x. if the median score was 5 points lower than the avage score on the exam, which of the following could be x?
a-70
b-75
c-80
d-90
e-95

I can't do this the proper way but guess and check is awesome.
Average equals 61 + x/5
I started in the middle at 80
Average then equals 77 and median is 75, FAIL
Trying 90 Failed
I know 75 fails
70 then WORKS
Took about 3 mins to solve though

 

[doc3232]

Streetwolf come please and do it properly.

 

[Bruinlove]

kaplans explanation sucks.. so can anybody explain this better to me

the scores on a certain exam were 60, 75, 100, 70 and x. if the median score was 5 points lower than the avage score on the exam, which of the following could be x?
a-70
b-75
c-80
d-90
e-95

Method #1: Look at all the numbers. All are multiple of 5s. So, the average must be multiple of 5 in order to be 5 greater than the median.
95 is the only one that gives an avg of multiple of 5.

Method #2: The order of scores is (60, 70, 75, 100). Thus, median can be either 70 or 75 depending on what the x is. If x is 70, median will be 70. If x is greater than or equal to 75, the median will be 75. Thus, possible avg is 75 or 80. Multiply these number by 5 and subtract 4 test scores.

 

[futuredent22]

I got 95. The equation I set up is:

(60+70+75+100+X)/5 = 75+5

This made the assumption that the median is 75, which is what the median would be for all answers B-E.

 

[Streetwolf]

kaplans explanation sucks.. so can anybody explain this better to me

the scores on a certain exam were 60, 75, 100, 70 and x. if the median score was 5 points lower than the avage score on the exam, which of the following could be x?
a-70
b-75
c-80
d-90
e-95

Mean = (305 + x)/5 = 61 + x/5
Median is 5 points lower than this = 56 + x/5

Realize that the median can either be 70 or 75 after reviewing the answer choices. By the above formula for median, that means x can either be 70 or 95.

Yeah, so two answers work. Try them.

 

[IWantH2O]

Mean = (305 + x)/5 = 61 + x/5
Median is 5 points lower than this = 56 + x/5

Realize that the median can either be 70 or 75 after reviewing the answer choices. By the above formula for median, that means x can either be 70 or 95.

Yeah, so two answers work. Try them.

i dont know bout 70 but the answer listed was 95

 

[futuredent22]

Both are correct

 

[Mamona]

i dont know bout 70 but the answer listed was 95

I got 95 as well

 

[doc3232]

Both are correct

It is a bad question.

They both work.

 

[Sublimation]

kaplans explanation sucks.. so can anybody explain this better to me

the scores on a certain exam were 60, 75, 100, 70 and x. if the median score was 5 points lower than the avage score on the exam, which of the following could be x?
a-70
b-75
c-80
d-90
e-95

Both answers A and E are correct.

A. 70+305=375/5=75 Therefore, (60, 70, 70, 75, 100) 70= 75(mean) -5

D 95+305= 400/5=80 Therefore, (60, 70, 75, 95, 100) 75= 80(mean) -5