SOLUTION: Hospital Records show that 12% of all patients are admitted for surgical treatment, 16% are admitted for obstetrics, and 2% receive both obstetrics and surgical treatments. If a n

Algebra ->  Probability-and-statistics -> SOLUTION: Hospital Records show that 12% of all patients are admitted for surgical treatment, 16% are admitted for obstetrics, and 2% receive both obstetrics and surgical treatments. If a n      Log On


   

Question 1038886: Hospital Records show that 12% of all patients are admitted for surgical treatment, 16% are admitted for obstetrics, and 2% receive both obstetrics and surgical treatments. If a new patient is admitted to the hospital, what is the probability that the patient will be admitted either for surgery, obstetrics, or both?
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
p(s) = .12
p(o) = .16
p(s and o) = .02

p(s or o) = p(s) + p(o) - p(s and o).

that would make p(s or o) = .12 + .16 - .02 = .28 - .02 = .26.

the assumption is that p(s and o) is being double counted because it's included in p(s) and it's included in p(o).

that's why you have to subtract one occurrence of it.