assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level.
n=500, x=300, 95 percent confidence

Question

assume that a random sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the given statistics and confidence level.
n=500, x=300, 95 percent confidence

amistre64 · Answer

nice, but not relevant to the question

anonymous · Answer

thats what i am saying.

amistre64 · Answer

$$E=z\sqrt{\frac{pq}{n}}$$

amistre64 · Answer

another way to look at this is:

$$E=z\sqrt{\frac{x(n-x)}{n^3}}$$

amistre64 · Answer

the z score of 95% is what ... 1.96 ?

amistre64 · Answer

does this look familiar?

anonymous · Answer

yes but i am still confused on how to find p hat. I know q hat is 1-phat

amistre64 · Answer

phat = x/n

amistre64 · Answer

$$\Huge \frac{pq}{n}=\frac{\frac{x}{n}\frac{n-x}{n}}{n}=\frac{x(n-x)}{n^3}$$

amistre64 · Answer

1.96sqrt(300*200/500^3) = .0429414...

amistre64 · Answer

if your not given decimal percents,   then to avoid excess calculations I would just use the n^3 version

anonymous · Answer

thank you i worked it out and got the same

amistre64 · Answer

youre welcome