Here is a sample, but failed. would you please help me? Thank you.

root@ht186w qt]# yum install qt4.7-devel
Loaded plugins: aliases, changelog, downloadonly, fastestmirror, filter-data, keys, kmod, list-data, priorities, protect-packages, protectbase, security, tmprepo, verify, versionlock
Loading mirror speeds from cached hostfile
Setting up Install Process
No package qt4.7-devel available.
Nothing to do