Node.js will not Update to Latest Version

I currently have node.js version v7.6.0

According to documentation, v8.5.0 is the latest version of node.

I have tried installing it using https://nodejs.org/en/

    node -v returns v7.6.0.

I have tried the following commands in Terminal:

    [sudo] npm install npm@latest -g    npm install npm@latest -g    sudo apt-get update    sudo n 0.8.21    sudo n latest    lsb_release -a

Each command appears to recognize and install the latest version, but the final message reads:

Installed: v7.6.0

I've altered my BASH Profile to include:

    /usr/local/bin/node    /usr/local/bin/npm

My version still shows v7.6.0 as the current version running.

Side Note:My NPM is up-to-date at version 5.4.2

Is there any other way to update my Node to the current version?