Theoretically yes, the Yahoo hosting plans include the use of PHP and MySQL which is what Joomla can run on. So then all you need is FTP site access (which I am sure they have) and you can upload your Joomla content.

However, the best thing to do is contact Yahoo and ask them if running a CMS is fine with the plan because some content management systems also need directory permission changes, write access to certain config files and more. They would be the best people to talk to about any complications that may arise.

Hope the CMS works out on Yahoo.

Try dreamhost http://dreamhost.pinologic.com to compare.