problem of biostat

Question

two drugs A and B are given below to two independs groups of 10 and 12 patients of hearts disease respectively. After 30 minutes the reduction of blood pressure due to two drugs are recorded are given below drug A : 7 16 14 9 10 11 6 8 9 10 . drug B : 10 12 16 14 11 12 13 8 12 15 9 12 . Which drugs show greater variation in reduction of blood pressure

Answer 1

Prince,

 

I would use the sample variance as the indicator of variation in each of the samples.

 

The formula for the sample variance is:

 

s² = [∑(X - mean)²]/(n -1)

 

You can calculate this for each group and the larger value is the group with the greater variation.  

 

To find out whether Drug A is significantly different from Drug B in terms of lowered BP, a test statistic would need to be calculated and then compared against a known distribution.  Most likely, you'd be doing a t-test since the sample size is < 30.