[chillacy]

I know nothing about insurance, but treating this like one of those crappy interview questions, I'd say you multiply the probability of an incident with the cost of that incident times 1 million people, and that's your expected cost per year. Then you look at how much you charge each person and see if they're willing to pay.

Probably as someone else mentioned, dental insurance is expensive because even though routine dental work is cheaper than getting cancer / breaking a bone, it happens 100% of the time.