Thread: Q19
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Old 06-10-2013, 10:21 PM
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yaser yaser is offline
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Default Re: Q20

Originally Posted by nkatz View Post
Is P(D|h=f) a function of D or h or both?
Let us first clarify the notions. The data set {\cal D} has one data point in it which is either +1 (heart attack) or -1 (no heart attack). Being a function of {\cal D} means being a function of that value (\pm 1), so indeed P({\cal D}|h=f) is a function of {\cal D}, and it so happens in this problem that the value is fixed at +1. The probability P({\cal D}|h=f) is also a function of h (which happens to be the same as f according to what we are conditioning on).

Since {\cal D} is fixed, this leaves P({\cal D}|h=f) as a function of h only.
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