Stats Help!

Just a couple quick questions!

Is there a formula to follow in order to find out how many intervals to use for a grouped frequency table? Or is it to your own discretion?

Also, can a distribution be both skewed to the left (negatively skewed) and bimodal?

Thanks!!

1) There is no authoritative guidance. What is it that you want to show? Pick an interval size that does not obscure what is wanted.

2) Can you draw it?