Question

What is the margin of error for a yes/no survey of 200 people with a proportion of 65% who answered "yes"?

Answer 1

A.±3.37%
B.±5.06%
C.±6.75%
D.±8.43%
E.±10.12%

Answer 2

@amistre64

Answer 3

I'm no statistics maven by any stretch of the imagination, but are you sure that's all of the information?

Answer 4

yep

Answer 5

thats all i see

Answer 6

Do you know (or can you find) the sample error?

Answer 7

sorry, standard error, not sample error

Answer 8

Ah, okay, got it.

Standard error for a sample proportion is going to be \[\sqrt{\frac{p(1-p)}{n}}\]where \(p = 0.65\) and \(n = 200\)

Answer 9

ummm im trying to lok it up but idk

Answer 10

Hey, you're in this class, I've never studied this stuff, I shouldn't be finding it more quickly than you do :-)

Answer 11

i actually failed algebra 2 and they gave me statistics so idk i've actaully nevver seen this stuff before

Answer 12

i dont think that comes out as any of the answer choices

Answer 13

im so confused...lol

Answer 14

if we just evaluate that square root, the value is \[\sqrt{0.65(1-0.65)/200} \approx 0.0337268\]which expressed as a percentage would be 3.37%. That's one of our answers. However, 200 * that number is also one of our answers...you'd be better off with a real statistics weenie here, I think. Why don't you take away my medal so that people will look at the problem? (I think many people don't bother looking at questions where medals have already been awarded, figuring there is little chance they'll be able to get one).

Answer 15

whats the other aswer that i could get?

Answer 16

200 * 0.0337268 = 6.74. That string of digits appears in your choices, too. No doubt one (or maybe both) of them is a "trap" answer for people who don't understand the problem. I don't want to be responsible for you falling into the trap :-)

Answer 17

what one do you think is the best option

Answer 18

Find someone who understands the material better than I do.

Answer 19

alright

Answer 20

@amistre64

Answer 21

I was looking at this page: http://stattrek.com/estimation/margin-of-error.aspx

Answer 22

its 3.37 my teacher told me

Answer 23

3.37%, not 3.37. Thanks for letting me know.