Question 186745
A survey of undergraduate students in the school of Businees at Northern University revealed the following regarding the gender and majors of the students: 
Major
Gender Accounting Management Finance Total 
Male...... 100...... 150....... 50... 300
Female.... 100....... 50....... 50... 200
Total..... 200...... 200...... 100... 500 
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What is the probaility of selecting a female student? 200/500 = 2/5
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What is the probability of selcting a finance or accounting major?(100+200)/500
= 3/5
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What is the probability of selecting a female or an accounting major? Which rule of addition did u apply? : (200+200-100)/500 = 3/5
P(A or B) = P(A)+P(B)-P(A and B)
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Are gender and major independent? Why?
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Comment: You could run a Chi-Sq. test to see if the rows and columns are
independent.  But I'm not sure you have studied that yet. If you have.
Ho: row and column factors are independent
Ha: they are dependent 
I ran a Chi-Sq test on the 2 x 3 matrix and got the following results:
test statistic: Chi-Sq = 31.25
p-value = 0.0000001637..
df = 2
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Conclusion: Reject Ho ; Gender and Major are not independent
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What is the probability of selecting an accounting major, given that the person selected is a male? P(acc|male) + [P(acc and male)/P(male) = 1/3
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Suppose two students are selected randomly to attend a lunch with the president of the University. What is the probability that both of these selected are accounting majors? 200C2/500C2 = 0.1595
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Cheers,
Stan H.