Install Qt 5.4 in Ubuntu 14.04

First you need to download according to your OS version(32 bit or  64-bit). 

Download link is below..

https://www.qt.io/download/

For 32bit

1)    wget http://download.qt-project.org/official_releases/qt/5.4/5.4.0/qt-opensource-linux-x86-5.4.0.run

2)    chmod +x qt-opensource-linux-x86-5.4.0.run

3)    ./qt-opensource-linux-x86-5.4.0.run

For 64bit

1)    wget http://download.qt-project.org/official_releases/qt/5.4/5.4.0/qt-opensource-linux-x64-5.4.0.run

2)    chmod +x qt-opensource-linux-x64-5.4.0.run

3)    ./qt-opensource-linux-x64-5.4.0.run

After this command  User Interface window will open then press next according to instruction. 

Note: Same way you can download any version just change 5.X according to version you want to install.