There are a good number of plugins to add Google Analytics code to WordPress, but I did the following:
Edit
header.php
Paste your tracking code directly after the opening tag
To edit header.php see the screenshot below:
!["googleAnalyticsWordpress"]("http://wiredin.co.za/academy/wp-content/uploads/2016/04/googleAnalyticsWordpress.png")
Click on “Theme Header” on the right side of the screen