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#1
12-04-2010
 USMLE Forums Addict Steps History: Step 1 Only Posts: 161 Threads: 29 Thanked 106 Times in 56 Posts Reputation: 116
NBME7- Biostatistics Question

A study is conducted to estimate the number of procedures performed by surgeons. A questionnaire is mailed to 8000 doc's,of these 70% respond. Which of the following most strongly suggests that the respondents represent a heterogeneous population with respect to number of procedures performed.
MEAN NUMBER OF PROCEDURES -- STANDARD DEVIATION
A) 4 -- 0.1
B) 7 -- 1.8
C) 11 -- 0.5
D) 13 -- 5.1
 The above post was thanked by: Amenah (08-25-2011)

#2
12-04-2010
 USMLE Forums Scout Steps History: 1+CK+CS+3 Posts: 12 Threads: 1 Thanked 7 Times in 5 Posts Reputation: 17

I think the larger is the standard deviation the more heterogenous is the group so I pick answer D
 The above post was thanked by: Amenah (08-25-2011)
#3
12-04-2010
 USMLE Forums Addict Steps History: Step 1 Only Posts: 161 Threads: 29 Thanked 106 Times in 56 Posts Reputation: 116

should we not calculate the S.E.M and then compare??
#4
12-04-2010
 USMLE Forums Scout Steps History: 1+CK+CS+3 Posts: 12 Threads: 1 Thanked 7 Times in 5 Posts Reputation: 17

Quote:
 Originally Posted by faith should we not calculate the S.E.M and then compare??
No you don't need that.
You don't need to calculate the 95% confidence interval. The SD alone gives you information on how widely distributed is your population.
 The above post was thanked by: wasify81 (12-04-2010)
#5
08-25-2011
 USMLE Forums Master Steps History: 1+CK+CS+3 Posts: 1,357 Threads: 194 Thanked 3,259 Times in 881 Posts Reputation: 3269

Quote:
 Originally Posted by faith should we not calculate the S.E.M and then compare??
Does not matter really. Here you have the SD.
You could calculate the SEM...SD/sqrt(N)...but in this case, the sqrt(N) would be the same number ...and you would end up with the same conclusion.
 The above post was thanked by: Amenah (08-25-2011)

 Tags Biostatistics-Epidemiology, Step-1-Questions

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