Draw a distribution diagram!
Octave, 34 32 bytes



@(a,b,n)hist(--a+randi(b-a,n,1))


Doesn't work on TIO, but works on Octave-online.net.

It creates a histogram (bar chart) looking like this:



I'd say that counts as "Any convenient format".

If non-zero bins must be shown, then this can be solved in 38 bytes: 

@(a,b,n)hist(--a+randi(b-a,n,1),a+1:b)