<PRE><B>Question 1010914</B>
 It is estimated that 89% of senior citizens suffer from sleep disorders and 9% suffer from anxiety. Moreover, 6% of senior citizens suffer from both sleep disorders and anxiety. 

(a) Find the probability that a senior citizen suffers from anxiety, given that he or she has sleep disorder. Round your answer to decimal places.
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P(a | sd) = p(a AND sd)/P(sd) = 0.06/(0.89) = 0.674
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(b) Given that a senior citizen suffers from anxiety, what is the probability that he or she also suffers from sleep disorder? Round your answer to decimal places.
P(ds | a) = P(ds AND a)/P(a) = 0.06/0.09 = 2/3
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Cheers,
Stan H. </PRE>