Answer:
0.6384
Step-by-step explanation:
Given that:
10-mg Atorvastatin Placebo Headache 15 65 No headache 17 3
Hence the total of number of patients = 15 + 65 + 17 + 3 = 100 patients
The number of patients with headache = 15 + 65 = 80 patients
Also, C(n, x) is the number of combinations in which n items can be chosen taken x at a time it is given by the formula:
[tex]C(n,x)=\frac{n!}{(n-x)!x!}[/tex]
The the probability that if two different subjects they both had a headache = [tex]\frac{C(80,2)}{C(100,2)}=\frac{\frac{80!}{(80-2)!2!} }{\frac{100!}{(100-2)!2!} } =\frac{3160}{4950}=0.6384[/tex]
