In: Statistics and Probability
Test whether people with a specific genetic marker are more likely to have suffered from clinical depression than people without the genetic marker, using the information that 38% of the 42 people in a sample with the genetic marker have had clinical depression while 12% of the 758 people in the sample without the genetic marker have had clinical depression.
Ans:
pooled proportion=(0.38*42+0.12*758)/(42+758)=0.13365
Test statistic:
z=(0.38-0.12)/sqrt(0.13365*(1-0.13365)*((1/42)+(1/758)))
z=4.82
p-value=P(z>4.82)=0.0000
Reject the null hypothesis.
There is sufficient evidence to conclude that people with a specific genetic marker are more likely to have suffered from clinical depression than people without the genetic marker.