General :: Compiling Main.c, Conflicting Types And Previous Declaration Was Here Errors

I'm trying to compile a main.c file that contains a while statement. Embedded in the while statement are functions that are being called. After the while statement, I have 2 more functions being called, one to find the average(getaverage), and one to print the results (printstuff). I also used a header file (my.h) that contains all of the needed #define and #include, along with each of the void function() statements.

There isn't any problems with the while statement/ the functions in while, but when I try and compile main.c I get the following errors:

main.c error: conflicting types for 'getaverage'
my.h error: previous declaration of 'getaverage'
and then the same thing for 'printstuff'