Question 871010

1)Use the contingency table below to compute the following probabilities, based on a random sample of a subject:


<img src="http://i150.photobucket.com/albums/s91/jim_thompson5910/SNAG_Program-0004a_zpscf6fd79d.png">



a) P(Male | Basketball) 


This is saying "Probability of picking a male given s/he likes basketball"


Look in the basketball column. There are 100 people total here. There are 60 of them who are male, so 60/100 = 6/10 = 3/5 is the probability 


P(Male | Basketball) = <font color="red">3/5</font>

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b) P(Female or Baseball) 


There are 120 females total (see the "total" in the "female" row). 

There are 120 baseball fans total (see the "total" in the "baseball" column). 

There are 50 baseball fans who are female (intersection of female row and baseball column)


So there are 120+120-50 = 240-50 = 190 people who either are female or like baseball (or are both female and like baseball). We subtract off that 50 because of the double counting.


So we have 190 people of what we're looking for out of 300 total people (bottom right corner). Divide the two: 190/300 = 19/30


P(Female or Baseball) = <font color="red">19/30</font>

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c) P(Football) 


There are 80 total football fans (male + female)


This is out of 300 people total


80/300 = 8/30 = 4/15


P(Football) = <font color="red">4/15</font>


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d) P(Male and Football)


There are 50 males who happen to like football as well. This is out of 300 people total.



50/300 = 1/6



P(Male and Football) = <font color="red">1/6</font>