Question 86761
Tests Done?
.........Yes... No......|Total
Age<65  0.321...0.124....|0.445
Age>=65 0.365...0.190....|0.555
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Total...0.686...0.314.... 1.000
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1) What is the probability that a pt. is under 65? Ans: 0.455
That a pt. is 65 or over ? Ans: 0.555
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2) What is the probability that the tests were done for a pt.? Ans: 0.686
That they were not done? Ans: 0.314
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3) Are the events A= (the pt. was 65 or older) and B= (the tests were done independent?
P(A)*P(B) = 0.555*0.686 = 0.38073
P(A|B) = 0.365
Ans: Since these are not the same the A and B are dependent.
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Were the tests omitted on older pts. more or less frequently than would be the case if testing were independent of age?
Ans: Yes, the percentage would be up to 38% instead of 36.5%
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Cheers,
Stan H.