1：Check whether Apache is already installed.

# rpm -qa | grep -i http

httpd-tools-2.2.8-3.i386
httpd-2.2.8-3.i386
[Note: This indicates that Apache 2.2.8 version is installed already]

2：Check whether latest version of Apache is available for installation using yum.

yum check-update httpd

Loaded plugins: refresh-packagekit
httpd.i386      2.2.9-1.fc9       updates
[Note: This indicates that the latest Apache version 2.2.9
       is available for upgrade]

3：Upgrade Apache to latest version using yum.