bash script reading an RSS feed and execute another script if result is greater than X

I'm a bit messed up with while read and If routines.

I'm trying to create a bash script for Linux which reads the processed clean numerical output from rsstail and if the numerical output is greater than 5.5 then it executes another script I already have.

The main command for rsstail I'm running is checking for the newest RSS every 3 seconds and gets the first clean 3-5 characters which are the numbers I need, using the following:

rsstail -i 3 -u http://someserver/somefile.xml -n 1 -N | cut -c 3-5

The output of that is a single number like

3.7

Then I need to compare constantly the numerical output and IF it is greater than 5.5, then execute another script I already have. If it is not, do nothing but continue to check the rsstail output for values greater than 5.5