algorithm for weighted ranking

IMDB的top250的电影weighted ranking的算法

weighted rating (WR) = (v ÷ (v+m)) × R + (m ÷ (v+m)) × C

 where:
  R = average for the movie (mean) = (Rating)
  v = number of votes for the movie = (votes)
  m = minimum votes required to be listed in the Top 250 (currently 1300)
  C = the mean vote across the whole report (currently 6.7)

for the Top 250, only votes from regular voters are considered.