Question 254938
j=probability john watches
m= probability jane watches
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Check the Venn diagram below
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{{{drawing( 300, 300, -5, 5, -5, 5,
  rectangle( -4.5, 4.5, 4.5, -3.5 ),
red( circle(- 1.5, 0, 2.5) ),
  green( circle( 2, 0, 2.25 ) ))}}}
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Lets take a weekly show for 10 weeks. j watches 4 shows and m watches 5 in that period.  The probability that John watches the show, given that Jane does, is 0.7 This means that while m is watching one of her five shows j is also watching .7 of the time so he is watching 5*.7=3.5 shows. That leaves him only 0.5 shows to watch on his own.
Now we divide the above numbers by 10 and do the Venn diagram. Put .05 in the red circle, .15 in the green circle and .35 in the intersection between the circles and .45 outside the circles for when nobody is watching the show so that the sum equals 1
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a) .35 the intersection.
b) .35/.4=.875
c) Yes. .05 for j and 1.5 for m
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E-mail me any more questions.
This is a tough one. Let me know if it is correct or not.
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Ed