Sometime Today, Rajen Parekh assembled some asciibets to say:
rpm, which in your case is libmng. Else, if you are sure that you have the correct file then put that file in /usr/lib and then force install the qt rpm (rpm -i --force <package>). And yes, also run ldconfig.
actually, use nodeps, not force. force is used when the package can cause conflicts with existing packages. nodeps is used to not check for dependencies.
Philip