I'm having trouble resizing some images inserted into posts. I can click on the image while editing the page and it gives me different sizes I can make the image. When I choose the smaller options like the thumbnail option it does shrink the image, but past a certain size changing the size doesn't seem to work. It looks like no matter what size I choose from the given list or in the custom size option I can't get the image bigger than about 400 pixels. I'd like to make images most of the width of the page.
Is there some sort of size limit for images built into the theme or something? Is there some way to get around this to insert images that are like 700 pixels wide into a page? I have some tables and flowcharts that need to be pretty large or else the text is not legible.
An example of a page where I am having this problem is http://www.stomponstep1.com/biostats/standard-deviation-mean-median-mode-robustness-in-skewed-right-positive-skew-skewed-left/
Thank you so much for any guidance you can provide!