document.write( "Question 1198690: There are 200 students in a particular graduate program at a state university. Of them, 110 are female and 125 are out- of state students. Of the 110 females, 70 are out - of - state students. Draw and label a Venn diagram depicting this information. \r
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document.write( "Are the events” female” and “ out - of - state student” independent? Are they mutually exclusive? Explain why or why not.
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document.write( "If one of these 200 students is selected at random, what is the probability that the student selected is an out - of - state student given this student is a female?\r
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Algebra.Com's Answer #832325 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Here's the Venn Diagram \n" ); document.write( " ![]() \n" ); document.write( "I started with the 70 female out-of-state students in the overlapped region of the two circles.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since there are 110 female students, there must be 110-70 = 40 female students who aren't out-of-state. \n" ); document.write( "In other words, these female students are in-state. \n" ); document.write( "This value goes inside the circle on the left, but outside the other circle.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 125 out-of-state students, which means 125-70 = 55 out-of-state students aren't female. \n" ); document.write( "This value goes inside the circle on the right, but outside the other circle.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The values in either circle add to 40+70+55 = 165 to represent the number of students who are female, out-of-state, or both. \n" ); document.write( "There are a total of 200 people surveyed, so we have 200-165 = 35 students who are neither female nor out-of-state. \n" ); document.write( "We'll have this final value outside of both circles. \n" ); document.write( "As a check, all four values should add to the grand total of 200. \n" ); document.write( "The rectangle represents the universal set, which means every value is inside it.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Here is another way to represent those set of values in a two-way table. \n" ); document.write( "
\n" ); document.write( "and this is what it looks like when we have row and column totals \n" ); document.write( "
\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Define these two events \n" ); document.write( "A = person selected is female \n" ); document.write( "B = person selected is out-of-state\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "From the venn diagram, and also the given info: \n" ); document.write( "P(A) = 110/200 = 0.55 \n" ); document.write( "P(B) = 125/200 = 0.625 \n" ); document.write( "P(A and B) = 70/200 = 0.35\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If events A and B were independent, then \n" ); document.write( "P(A and B) = P(A)*P(B) \n" ); document.write( "would be a true equation.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's see if that's the case \n" ); document.write( "P(A)*P(B) = 0.55*0.625 = 0.34375 \n" ); document.write( "which is close to the 0.35 calculated earlier, but not quite there. \n" ); document.write( "Therefore, P(A and B) = P(A)*P(B) is false in this case; meaning A and B are not independent.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now on to see if the events are mutually exclusive. \n" ); document.write( "A and B are mutually exclusive if and only if \n" ); document.write( "P(A and B) = 0 \n" ); document.write( "but \n" ); document.write( "P(A and B) = 0.35 which clearly is nonzero. \n" ); document.write( "Events A and B are are not mutually exclusive\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now onto the last part of this question: If one of these 200 students is selected at random, what is the probability that the student selected is an out-of-state student given this student is a female?\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The part at the end \"given this student is a female\" tells us that we focus on everyone inside the \"female\" circle of the venn diagram. \n" ); document.write( "Ignore anyone else.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Of those 110 women, 70 are out-of-state \n" ); document.write( "70/110 = 7/11 is the probability of selecting an out-of-state person if we know 100% the person is a woman.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7/11 = 0.63636 = 63.636% approximately\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "-------------------------------------------------------\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Summary:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question: Are the events \"female\" and \"out-of-state student\" independent? \n" ); document.write( "Answer: No, the events are not independent.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question: Are the events \"female\" and \"out-of-state student\" mutually exclusive? \n" ); document.write( "Answer: No, the events are not mutually exclusive.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Question: If one of these 200 students is selected at random, what is the probability that the student selected is an out-of-state student given this student is a female? \n" ); document.write( "Answer: 7/11 \n" ); document.write( " \n" ); document.write( " |