use the given data to find the minimum sample size required to estimate a population proportion or percentage.

Margin of error: seven percentage points, confidence level 95%: from prior study. phat is estimated by the decimal equivalent of 48%.
n=?

Question

use the given data to find the minimum sample size required to estimate a population proportion or percentage. 

Margin of error: seven percentage points, confidence level 95%: from prior study. phat is estimated by the decimal equivalent of 48%.
n=?

amistre64 · Answer

remember how to find E?  this is just solving that for n

amistre64 · Answer

$$E=z\sqrt{\frac{pq}{n}}$$
$$\sqrt n=\frac zE \sqrt{pq}$$
$$ n=\left(\frac zE \right)^2~pq$$

amistre64 · Answer

$$n=\left(\frac {1.96}{.07} \right)^2~.48(.52)$$

amistre64 · Answer

and round up ...

anonymous · Answer

would it be 2018

amistre64 · Answer

no

amistre64 · Answer

http://www.wolframalpha.com/input/?i=.48%28.52%29%281.96%2F.07%29%5E2

anonymous · Answer

so 196

amistre64 · Answer

id go with 196 ... assuming of course i read this correctly :)

anonymous · Answer

since i must round to the nearest integer?

anonymous · Answer

thank you for the help

amistre64 · Answer

youre welcome