class Array

# File lib/gauntlet.rb, line 315
def average
  return self.sum / self.length.to_f
end

# File lib/gauntlet.rb, line 319
def sample_variance
  avg = self.average
  sum = 0
  self.each { |i| sum += (i - avg) ** 2 }
  return (1 / self.length.to_f * sum)
end

# File lib/gauntlet.rb, line 326
def stddev
  return Math.sqrt(self.sample_variance)
end

# File lib/gauntlet.rb, line 309
def sum
  sum = 0
  self.each { |i| sum += i }
  sum
end