Error Message When Installing Rubygems in Tutorial

I'm in the beginning stages (Section 1.2.2) of Hartl's RoR tutorial and, after installing Ruby, can't get RubyGems installed appropriately. See sequence below:

Hansell-Shooks-MacBook-Pro:~ hansellshook$ rvm install 1.9.2
Installing Ruby from source to: /Users/hansellshook/.rvm/rubies/ruby-1.9.2-p290, this may take a while depending on your cpu(s)...

ruby-1.9.2-p290 - #fetching 
ruby-1.9.2-p290 - #extracted to /Users/hansellshook/.rvm/src/ruby-1.9.2-p290 (already   extracted)
Fetching yaml-0.1.4.tar.gz to /Users/hansellshook/.rvm/archives
Extracting yaml-0.1.4.tar.gz to /Users/hansellshook/.rvm/src
Configuring yaml in /Users/hansellshook/.rvm/src/yaml-0.1.4.
Compiling yaml in /Users/hansellshook/.rvm/src/yaml-0.1.4.
Installing yaml to /Users/hansellshook/.rvm/usr
ruby-1.9.2-p290 - #configuring 
ruby-1.9.2-p290 - #compiling 
ruby-1.9.2-p290 - #installing 
Removing old Rubygems files...
Installing rubygems-1.8.10 for ruby-1.9.2-p290 ...
Installation of rubygems completed successfully.
ruby-1.9.2-p290 - adjusting #shebangs for (gem irb erb ri rdoc testrb rake).
ruby-1.9.2-p290 - #importing default gemsets (/Users/hansellshook/.rvm/gemsets/)
Install of ruby-1.9.2-p290 - #complete 
Hansell-Shooks-MacBook-Pro:~ hansellshook$ rvm --create 1.8.7-p352@rails2tutorial 
Hansell-Shooks-MacBook-Pro:~ hansellshook$ rvm --create use 1.9.2-p290@rails3tutorial
Using /Users/hansellshook/.rvm/gems/ruby-1.9.2-p290 with gemset rails3tutorial
Hansell-Shooks-MacBook-Pro:~ hansellshook$ rvm --defa开发者_高级运维ult use 1.9.2-p290@rails3tutorial
Using /Users/hansellshook/.rvm/gems/ruby-1.9.2-p290 with gemset rails3tutorial
Hansell-Shooks-MacBook-Pro:~ hansellshook$ which gem
/Users/hansellshook/.rvm/rubies/ruby-1.9.2-p290/bin/gem
Hansell-Shooks-MacBook-Pro:~ hansellshook$ [sudo] ruby setup.rb
-bash: [sudo]: command not found

After reading the sequence, it seems to me the installation already took place when installing Ruby 1.9.2. However, I can't proceed any further from this point (which is to install Rails). Anyone know what I might be missing?

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Don't type in the brackets around sudo; that's to indicate the sudo is optional/may not be necessary/may not apply to your system. You're running a Mac, so you can use it.