The Emergency Room
September 23rd, 2013 at 3:31:23 PM
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Upon arrival at Kranker Hospital's emergency room, patients are categorized according to their condition as critical, serious, or stable. In the past year:
(i) 10% of the emergency room patients were critical;
(ii) 30% of the emergency room patients were serious;
(iii) the rest of the emergency room patients were stable;
(iv) 40% of the critical patients died;
(vi) 10% of the serious patients died; and
(vii) 1% of the stable patients died.
what is the probability that a survivor was categorized as serious upon arrival?
(i) 10% of the emergency room patients were critical;
(ii) 30% of the emergency room patients were serious;
(iii) the rest of the emergency room patients were stable;
(iv) 40% of the critical patients died;
(vi) 10% of the serious patients died; and
(vii) 1% of the stable patients died.
what is the probability that a survivor was categorized as serious upon arrival?
September 23rd, 2013 at 3:37:40 PM
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29.2207792%
"For with much wisdom comes much sorrow." -- Ecclesiastes 1:18 (NIV)
September 23rd, 2013 at 3:45:27 PM
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26%, but I remain skeptical about the method I used..
EDIT Correction : 29.22%
But much happier about my method.
EDIT Correction : 29.22%
But much happier about my method.
"Then you can admire the real gambler, who has neither eaten, slept, thought nor lived, he has so smarted under the scourge of his martingale, so suffered on the rack of his desire for a coup at trente-et-quarante" - Honore de Balzac, 1829
September 23rd, 2013 at 3:47:57 PM
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Quote: Wizard29.2207792%
I cannot believe I actually got the same answer as the WIZARD!!!
I am elated!!!
September 23rd, 2013 at 4:00:20 PM
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Did you use a speed count to get the answer ?
Shed not for her
the bitter tear
Nor give the heart
to vain regret
Tis but the casket
that lies here,
The gem that filled it
Sparkles yet
September 23rd, 2013 at 4:08:07 PM
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Quote: BuzzardDid you use a speed count to get the answer ?
Buzz - I would have expected that comment if I got the answer wrong LOL
September 23rd, 2013 at 5:41:35 PM
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With work.
Consider 1,000 patients.
100 are critical. 60 of them survive
300 are serious. 270 survive.
600 are fine. 594 survive.
Total number of survivors = 924
270 / 924 = .2922.
Consider 1,000 patients.
100 are critical. 60 of them survive
300 are serious. 270 survive.
600 are fine. 594 survive.
Total number of survivors = 924
270 / 924 = .2922.
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You want the truth! You can't handle the truth!
September 23rd, 2013 at 6:17:49 PM
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Wow, I did it the same way boyimbo did!
A falling knife has no handle.
September 24th, 2013 at 4:26:18 AM
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boymimbo's answer is delightfully simple! Here is the solution given given on the actuarial exam answer sheet:
P[ser/surv] = P[surv/ser] P[ser] / (P[surv/crit]P[crit]+P[surv/ser]P[ser]+P[surv/stab]P[stab]) =
(0.9)(0.3)/[(0.6)(0.1)+(0.9)(0.30+(0.99)(0.6)] = ?
using the Bayes rule. Kudos to boymimbo!
P[ser/surv] = P[surv/ser] P[ser] / (P[surv/crit]P[crit]+P[surv/ser]P[ser]+P[surv/stab]P[stab]) =
(0.9)(0.3)/[(0.6)(0.1)+(0.9)(0.30+(0.99)(0.6)] = ?
using the Bayes rule. Kudos to boymimbo!
September 24th, 2013 at 4:28:22 AM
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Quote: puzzlenutI would like to read the answers but the spoiler boxes won't open. I am logged in and have tried both Firefox and Chrome browsers.
click the quote botton
“Man Babes” #AxelFabulous
September 24th, 2013 at 7:01:11 AM
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Gonna make my guess before reading answers...
27.8%
September 24th, 2013 at 7:05:33 AM
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Quote: ewjones080Gonna make my guess before reading answers...
27.8%
Strange, I was off by two percent only.. Wonder if I just did a calculation error..
