Ubuntu Software Center is Prompting for Root

Situation:
Trying to install package using Ubuntu Software Center on Ubuntu 12.04 LTS(Precise)

Problem:
The user is prompted for the root password instead of their own

Solution:
Edit  /etc/polkit-1/localauthority.conf.d/51-ubuntu-admin.conf to include the user or their group. Here is an example of the contents of this file:

[Configuration]
AdminIdentities=unix-group:administrators;unix-user:johnsmith

References:

1. pklocalauthority - PolicyKit Local Authority

2. Ubuntu forums