Can you help me find the sample size for this problem?

[ohsaki_chan]

Find the minimum sample size you should use to assure that your estimate of p(w/ umlaut) will be within the required margin of error around the population p.

Margin of error: 0.025; confidence level: 96%; p (w/ umlaut) and q(w/ umlaut) are unknown.

Could you do it step by step or recommend a calculator that would automatically do it for me? Thanks.

 

[tkhunny]

\(\displaystyle \frac{t^{2} \cdot s^{2}}{d^{2}}\)

s is easy enough from p and q
d is given
Look up t in a table.