Are you good in Math????

[Ocean5]

---

Members don't see this ad.

Hi every one, my friend sent me a question that I'm unable to answer , please let me know what is the answer and how do we get it. I suppose it should be easy for you guys, since I never took math , it is not easy for me. Here we go:

From 30 question, 1 point each, the average was 89%, with a standard deviation of 4%. If Sarah scored inside of three standard deviation for the test, how many possible percent scores could Sarah have?

1) what is the range of scores and how do you get it?
2)what is the full list that is inside our standard deviation.
3)what is the final answer.

Tip: final answer should be one of these: 5, 6, 7, 8, 9
Thank you very much for trying to help.

 

[joonkimdds]

I believe this is statistic problem that doesn't belong to DAT math section.
I leanrned how to find range, standard deviation in stat but I forgot 😛

I think you can use TI-83 plus calculator, go to math and there is StanDev button and ....hm... anyway there is a way ~ ok? LOL. sorry.

 

[Streetwolf]

Hi every one, my friend sent me a question that I'm unable to answer , please let me know what is the answer and how do we get it. I suppose it should be easy for you guys, since I never took math , it is not easy for me. Here we go:

From 30 question, 1 point each, the average was 89%, with a standard deviation of 4%. If Sarah scored inside of three standard deviation for the test, how many possible percent scores could Sarah have?

1) what is the range of scores and how do you get it?
2)what is the full list that is inside our standard deviation.
3)what is the final answer.

Tip: final answer should be one of these: 5, 6, 7, 8, 9
Thank you very much for trying to help.

Average 89% and std dev 4% so the range is 89-12, 89+12 = [77, 101] but the test only goes to 100% so it's [77, 100]. That's 24 percent and definitely not on your answer list.

But if it really is asking about how many questions she got right (that seems more logical) then you know 77% of 30 is 23.1 so she had to have gotten at least 24 questions right. And the top percent is 100% which is all 30. So she could have gotten 7 possible raw scores. [24, 25, 26, 27, 28, 29, 30]

FYI: The answer would be 8 if they count a 23/30 as rounding up to 77%. I didn't. 23/30 ~ 76.67

 

[Shunwei]

Average 89% and std dev 4% so the range is 89-12, 89+12 = [77, 101] but the test only goes to 100% so it's [77, 100]. That's 24 percent and definitely not on your answer list.

But if it really is asking about how many questions she got right (that seems more logical) then you know 77% of 30 is 23.1 so she had to have gotten at least 24 questions right. And the top percent is 100% which is all 30. So she could have gotten 7 possible raw scores. [24, 25, 26, 27, 28, 29, 30]

Actually, I would argue that it is 8 possible raw scores, because 23/30 would be 76 2/3 which I assume can be reasonably rounded to 77, just hitting the bottom end of three standard deviations. I could be wrong about this assumption, though.

 

[Streetwolf]

Actually, I would argue that it is 8 possible raw scores, because 23/30 would be 76 2/3 which I assume can be reasonably rounded to 77, just hitting the bottom end of three standard deviations. I could be wrong about this assumption, though.

Haha I actually edited that in right after I submitted what you quoted.

 

[Ocean5]

Thank you very much. I appreciate you exs. Now I know what is goin on. 🙂