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  #1  
Old 03-11-2016
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Default Help with this stats question!

Someone sent me this question and for the life of me I can't solve it! Please help
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  #2  
Old 03-11-2016
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What we know from the information provided is that there were at least 1250 people that had the condition during the five-year period. Per year that translates to 250... but since the population of the town is 500,000 and the question is asking for the annual prevalence per 1,000,000... we have to multiply that value by two to get 500. But then we also have the additional 100 new cases that occurred during that five-year period. Suggesting that those cases aren't included in the 1250 cases registered by death certification, we can add another 40 to the original 500 to get 540.

But 540 is not listed as one of the answers, so I’m stumped. However, considering there are grammar and punctuation errors in the question… maybe the author got it wrong.
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  #3  
Old 03-11-2016
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I tried I got 0.04 instead
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  #4  
Old 03-11-2016
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Quote:
Originally Posted by Kruno View Post
What we know from the information provided is that there were at least 1250 people that had the condition during the five-year period. Per year that translates to 250... but since the population of the town is 500,000 and the question is asking for the annual prevalence per 1,000,000... we have to multiply that value by two to get 500. But then we also have the additional 100 new cases that occurred during that five-year period. Suggesting that those cases aren't included in the 1250 cases registered by death certification, we can add another 40 to the original 500 to get 540.

But 540 is not listed as one of the answers, so I’m stumped. However, considering there are grammar and punctuation errors in the question… maybe the author got it wrong.
Yeah I did it in the same way but the marked answer was 400. Maybe you're right and it's incorrect, but I was wondering if the one year survival rate had something to do with it?
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  #5  
Old 03-11-2016
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Quote:
Originally Posted by wa87el View Post
I tried I got 0.04 instead
Hey that might be correct...how did you get that answer?
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  #6  
Old 03-11-2016
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Quote:
Originally Posted by drinwaiting View Post
Yeah I did it in the same way but the marked answer was 400. Maybe you're right and it's incorrect, but I was wondering if the one year survival rate had something to do with it?
i think that the one year survival is just their way of trying to say that the prevalence was not 1250 across the five years, but one fifth of that.
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  #7  
Old 03-11-2016
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Ok , this is what I think and It can be totally wrong ..

Prevalence (%) =( no. of cases of have the dz / Total population ) * 100
so the total population is 500 , 000
so the number of cases who have the dz is 100 ( this should be during the 5th year ) as they calculated the number of patient who still have cancer Y during the 5 year , right ? since It has a zero yearly survival rate .. i.e no patients with cancer Y from the first 4 years will be included in those 100.

I think the 1250 dead patients is a distractor.

(100/500,000) * 100 = 0.02 ( for half a million )
0.02 * 2 = 0.04

I know totally wrong.
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  #8  
Old 03-11-2016
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I was googling prevalence earlier on ..
Some formula are multiplied by 1000 instead of 100 " And I don't know why ! "

So I was thinking if we multiplied the prevalence using 1 million instead of 100 in the original formula we will get 400 ..

Since they mentioned per million in the question ..
DAMN I m so screwed up.
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  #9  
Old 03-11-2016
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Whether I was wrong or right I spend over 30 minutes about this question , so in the real test I should just pick up the first choice and BAM Next!
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