Understanding the Calculation of Hospital Emergency Visits A ∩ B and A U B

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The discussion focuses on the calculations of hospital emergency visit events A ∩ B and A U B. Participants clarify that A ∩ B represents the intersection of events, while A U B represents their union. There is confusion regarding the inclusion of the number 242 in the calculations, which is identified as a typo that should be added. Additionally, the number 953 is correctly included in the union calculation, as it represents a specific subset of visits. Overall, the conversation highlights the importance of accurate data entry in statistical calculations.
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Homework Statement
A ∩ B and A U B
Relevant Equations
The question is taken from a Book. I don't understand how A ∩ B and AUB is calculated?
A ∩ B and A U B
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robax25 said:
I don't understand how A ∩ B and AUB is calculated?
The text in the first image describes the events A and B. In words, what does the event A ∩ B mean? What does the event A U B mean?

Per the forum rules, you must show some effort. I've cut you some slack here by not issuing a warning.
 
If I calculate A u B = 5292 + 270 + 246 but there is 242 as well. why is not 242 added? The second question is that A ∩ B = 5292 +953 - 195 but why does he add 953 to the equation?
 
robax25 said:
If I calculate A u B = 5292 + 270 + 246 but there is 242 as well. why is not 242 added? The second question is that A ∩ B = 5292 +953 - 195 but why does he add 953 to the equation?
The ##242## should be added. It looks like a typo.

##953## is the total number of LWBS, which is set ##B##.
 
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robax25 said:
The second question is that A ∩ B = 5292 +953 - 195 but why does he add 953 to the equation?
This is misreading their answer. They are saying that the count of ##A \cup B ## is 5292+953-195, not ##A \cap B##.
 
robax25 said:
If I calculate A u B = 5292 + 270 + 246 but there is 242 as well. why is not 242 added? The second question is that A ∩ B = 5292 +953 - 195 but why does he add 953 to the equation?
I agree with @PeroK .

5292 + 270 + 246 = 5808 , but Book has the result being 6050 .

Looking further, 6050 − 5808 = 242 .

So, clearly the 242 was omitted mistakenly.
 
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I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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