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#1
07-17-2011
 USMLE Forums Addict Steps History: 1 + CK Posts: 197 Threads: 51 Thanked 93 Times in 35 Posts Reputation: 103
biostat confidence interval question?

95 % confidence interval of two cardiac drugs x and y is as follows:
X= 2.2 - 3.5 and cardiac index 2.7 L/ m cube
Y= .6 - 1.6 and cardiac index 1.3 L/m cube

A test of significance is done to get a p value of .1

What's the likelihood that the the difference between cardiac index of X and Y is just by chance ?

a-0%
b-95%
c-97.5%
d-66.5%

#2
07-17-2011
 USMLE Forums Addict Steps History: 1 + CK Posts: 197 Threads: 51 Thanked 93 Times in 35 Posts Reputation: 103

pls explain the answer my friends
#3
07-17-2011
 USMLE Forums Master Steps History: 1+CK+CS+3 Posts: 1,357 Threads: 194 Thanked 3,268 Times in 881 Posts Reputation: 3278

is this NBME?

#4
07-17-2011
 USMLE Forums Addict Steps History: 1 + CK Posts: 197 Threads: 51 Thanked 93 Times in 35 Posts Reputation: 103

nope.....but i think i saw one similar one one of those and so i wanna crack similar ones ...hoof...biostat a headache
#5
07-17-2011
 USMLE Forums Scout Steps History: Step 1 Only Posts: 11 Threads: 1 Thanked 7 Times in 4 Posts Reputation: 17

Quote:
 Originally Posted by dr.dhruvdesai nope.....but i think i saw one similar one one of those and so i wanna crack similar ones ...hoof...biostat a headache
So can you please tell us what is your source of the questions. I am not opening your threads because am thinking they are NBME, but if you tell us the source we'll be relieved
 The above post was thanked by: jahn77 (07-17-2011)
#6
07-18-2011
 USMLE Forums Addict Steps History: Step 1 Only Posts: 127 Threads: 21 Thanked 103 Times in 53 Posts Reputation: 113

Quote:
 Originally Posted by dr.dhruvdesai 95 % confidence interval of two cardiac drugs x and y is as follows: X= 2.2 - 3.5 and cardiac index 2.7 L/ m cube Y= .6 - 1.6 and cardiac index 1.3 L/m cube A test of significance is done to get a p value of .1 What's the likelihood that the the difference between cardiac index of X and Y is just by chance ? a-0% b-95% c-97.5% d-66.5%
its B....coz p value is 0.1,,,,,null hypothesis cant be rejected...in reality there is no difference..but given data suggest that 95% probability that both group have difference...so all 95% confidence is by chance....very low power study and high bete error...here beta error is 95%..

 Tags Biostatistics-Epidemiology, Step-1-Questions

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