Array#include? is slow; use Set#include?

require 'benchmark/ips'
require 'set'

ary = []
5000.times { ary << rand.round(6) }
set = ary.to_set

Benchmark.ips do |x|
  x.report("Array#include?") { ary.include?(rand.round(6))}
  x.report("Set#include?")   { set.include?(rand.round(6))}
end

Calculating -------------------------------------
      Array#include?       374 i/100ms
        Set#include?     60669 i/100ms
-------------------------------------------------
      Array#include?     3780.7 (±1.1%) i/s -      19074 in   5.045665s
        Set#include?  2078044.8 (±3.5%) i/s -   10374399 in   5.000050s