Question 1132704
90% half-interval is z*sqrt(p*(1-p)/n) where z=1.645 and p is the point estimate of yellow or 159/579=0.275
half-interval is 1.645* sqrt (0.275*0.725/579)=0.0301
Therefore, the full interval is 0.275+/-1.645* sqrt (0.275*0.725/579)
the interval is (0.245, 0.305)
because 0.25 is within the confidence interval, the results to not contradict expectations.