Statistics can be used for benevolent purposes or for evil ones. Then there’s the middle ground, which is where this column resides. Once each month, I’ll suggest ways in which you can exploit data to improve your lot in everyday life. I won’t advocate that you do anything illegal or (in my opinion) immoral. But statistical analysis is being used, and not always to your benefit, by everyone from your cable company to your real estate broker. Consider this your chance to fight back. This week in article for the Times Magazine, we take a look at that confounding multipiece puzzle of modern life: the local salad bar.