It is known that 25% of inhabitants of a community favor a political party A. A random sample of 20 inhabitants was selected from the community and each person was asked he/she will vote for party A in an impending election. This follows a Binomial distribution, what is the probability that:
(i) exactly two persons will vote for party A?
(ii) at least three persons will vote for party A?
(iii) fewer than two persons will vote for party A?

There are two major tests of readiness for college: the act and the sat. act scores are reported on a scale from 1 to 36. the distribution of act scores in recent years has been roughly normal with mean µ = 20.9 and standard deviation s = 4.8. sat scores are reported on a scale from 400 to 1600. sat scores have been roughly normal with mean µ = 1026 and standard deviation s = 209. reports on a student's act or sat usually give the percentile as well as the actual score. the percentile is just the cumulative proportion stated as a percent: the percent of all scores that were lower than this one. tanya scores 1260 on the sat. what is her percentile (± 1)?