compare with correct values
compare with correct values

* spec/ruby/shared/rational/exponent.rb: compare with
  mathematically expected values without errors.

git-svn-id: ab86ecd26fe50a6a239cacb71380e346f71cee7d@63677 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

eregon/rubyspec,nobu/rubyspec,ruby/spec,nobu/rubyspec,eregon/rubyspec,nobu/rubyspec,ruby/rubyspec,ruby/rubyspec,ruby/spec,eregon/rubyspec,ruby/spec