$ sudo apt-get update
$ sudo apt-get install libgraphite-php 

libgraphite-php is installed in your system.

Make ensure the libgraphite-php package were installed using the commands given below,

$ sudo dpkg-query -l | grep libgraphite-php *

You will get with libgraphite-php package name, version, architecture and description in a table

libgraphite-php package basic information: