gistfile1.rb

require 'pp' #lets make things look pretty shall we

days=5
dataset=[25.0000,24.8750,24.7813,24.5938,24.5000,24.6250,25.2188,27.2500,26.2500,26.5938]
weighted_avgs = []

#lets break the data down to "days" size blocks - we'll only do calculations on full sets

dataset.each_cons(days) { |block|
  puts "Working with "
  pp block
  puts "Beginning iteration"
  tot = 0
  #we reverse here to make it easier to use index + 1 as the multiplier
  block.reverse.each_with_index { |daily_val, day|
    multiplier = day + 1
    weighted_val = daily_val * multiplier
    tot += weighted_val
    pp [daily_val, multiplier, weighted_val, tot]
  }
  puts "End iteration"
  weighted_avg = tot / (days * (days + 1) / 2 )
  puts "Weighted average for block is #{weighted_avg}"
  weighted_avgs << weighted_avg
}

puts "All done - here are the weighted averages"

pp weighted_avgs