Confidence Interval - Statistics?

After the football team once again lost a game to the college's arch rival, the alumni association conducted a survey to see if alumni were in favor of firing the coach. An SRS of 100 alumni from population of all living alumni was taken. 64 of the alumni in the sample were in favor of firing the coach. Let p represent proportion of living alumni who favor firing the coach.



Give 95% confidence interval for p.Confidence Interval - Statistics?
From http://en.wikipedia.org/wiki/Binomial_co鈥?/a>

Normal approximation confidence interval CI = p+/-Z*sqrt(p(1-p)/N)

where p is the sample proportion, Z is the sigma multiple associated

with the confidence limit, and N is the sample size. In this case

p=64/100, Z=1.96 (for 95% two-sided) and N=100, so CI = 0.546 to 0.734.

yamaha atv