A random sample of 100 undergraduate students at a university found that 78 of them had used the university library’s website to find resources for a class. What is the margin of error for the true proportion of all undergraduates who had used the library’s website to find resources for a class?
A. 0.04
B. 0.08
C. 0.1
D. 0.12

Question

A random sample of 100 undergraduate students at a university found that 78 of them had used the university library’s website to find resources for a class. What is the margin of error for the true proportion of all undergraduates who had used the library’s website to find resources for a class?
A. 0.04
B. 0.08
C. 0.1
D. 0.12

madeline4giles852 · Answer

Please help will medal

perfecta · Answer

It depends upon the confidence level (99%, 95%, etc) of the sample. In this case, the population size is 100, and the sample size is 78. If it's in a 99% confidence level, margin of error is 7 (So between 71 - 85 undergrads). If it's in a 95% confidence level, the margin of error is 6 (So between 72 - 84 undergrads).

mww · Answer

Use this formula
	
$$SE _{p } = \sqrt{\frac{ p(1-p) }{ n }}$$

where p is the proportion and n is total sample size

perfecta · Answer

what is 78(100-78)/100^3 ?
after that sqrt it

madeline4giles852 · Answer

88.317?

madeline4giles852 · Answer

@PerfectA

perfecta · Answer

Yes that should be If I'm not mistaking 
@madeline4giles852