$ sudo apt-get update
$ sudo apt-get install libkunitconversion4 

libkunitconversion4 is installed in your system.

Make ensure the libkunitconversion4 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libkunitconversion4 *

You will get with libkunitconversion4 package name, version, architecture and description in a table

libkunitconversion4 package basic information: