def std(bia, nums)
  sum = 0.0
  count = 0.0
  nums.each { |plus|
        sum += plus
        count += 1
        }
  puts "The sum of numbers in the array is: #{sum}"
  puts "The total numbers in your array is: #{count}"
  mean = sum / count
  puts "The mean of all the numbers in your array is: #{mean}"

    if bia == "biased"
    bia_nums = 0.0
    nums.each { |a| bia_nums += ((mean - a)**2) }
    print bia_nums
    stddev_biased = Math.sqrt(bia_nums / (count - 1))
  puts "The biased standard deviation is: #{stddev_biased}"

    elsif bia == "unbiased"
    unbia_nums = 0.0
    nums.each { |a| unbia_nums += ((mean - a)**2) }
    print bia_nums
    stddev_unbiased = Math.sqrt(unbia_nums / (count))
  puts "The biased standard deviation is: #{stddev_unbiased}"


    else
    print 'That is not the right syntax, use std("biased", [1,2,3])'
    end
end