Post #3 in this thread provides an example to follow: http://www.mathhelpforum.com/math-he...-homework.html
Note that in your case, instead of using you need to use where .
What proportion of pizza restaurants that are primarily fro walk-in business have a salad bar? Suppose that, in an effort to determine this figure, a random sample of 1,250 of these restaurants across the United States base on the Yellow Pages is called. If 975 of the restaurants sampled have a salad bar, what is the 98% confidence interval for the population proportion? State what the confidence interval means.
Post #3 in this thread provides an example to follow: http://www.mathhelpforum.com/math-he...-homework.html
Note that in your case, instead of using you need to use where .