Question 266359:  A recent study of 300 patients found that of 100 alcoholic patients, 87 had elevated cholesterol levels, and of 200 nonalcoholic patients, 43 had elevated cholesterol levels. If a patient is selected at random, find the probability that the patient is the following:
 
a. An alcoholic with elevated cholesterol 
b. A nonalcoholic 
c. A nonalcoholic with nonelevated cholesterol level.
 
Thanks! 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! A recent study of 300 patients found that of 100 alcoholic patients, 87 had elevated cholesterol levels, and of 200 nonalcoholic patients, 43 had elevated cholesterol levels. If a patient is selected at random, find the probability that the patient is the following: 
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Procedure: 
1st: I sketched a contingency table with 2 rows(alc and non-alc) and  
2 columns (high choles and low choles) 
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2nd: I put the given numbers into the contingency table and filled  
in the missing numbers. 
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Find the probability that the patient is the following: 
  
a. An alcoholic with elevated cholesterol: 87/300 
b. A nonalcoholic: 200/300 
c. A nonalcoholic with nonelevated cholesterol level: 43/300 
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Cheers, 
Stan H.  
 
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