Well, to use the numbers given, if P(death) when you don’t wear a seatbelt equals 1 and P(death) when you do equals 0.55, and 53 people die not wearing a seatbelt and 47 die wearing one, then 1 x A1 = 53 and 0.55 x A2 = 47. A1=53 and A2=85.45. A2/(A1+A2) = 0.617. So 62% of people are wearing a seatbelt at any given time.
I’m assuming they’re calcing the two figures given the same methods which is not a given. They might be using real world figures for the former statistics and car crash simulator numbers for the latter statistics which would make more sense but throw my calculation off. 62% seems low to me.
That’s irrelevant. As long as the ratio of seatbelt to not seatbelt is 55⁄100, you’ll end up with the same answer. ~seatbelt could be 0.1 or 0.03 or 0.00007.
Well, to use the numbers given, if P(death) when you don’t wear a seatbelt equals 1 and P(death) when you do equals 0.55, and 53 people die not wearing a seatbelt and 47 die wearing one, then 1 x A1 = 53 and 0.55 x A2 = 47. A1=53 and A2=85.45. A2/(A1+A2) = 0.617. So 62% of people are wearing a seatbelt at any given time.
I’m assuming they’re calcing the two figures given the same methods which is not a given. They might be using real world figures for the former statistics and car crash simulator numbers for the latter statistics which would make more sense but throw my calculation off. 62% seems low to me.
I am certain that the P(death|~seat belt) != 1.
That’s irrelevant. As long as the ratio of seatbelt to not seatbelt is 55⁄100, you’ll end up with the same answer. ~seatbelt could be 0.1 or 0.03 or 0.00007.