A study is conducted to determined if there is a greater rate of heart disease in lefties vs. righties. A random sample of 500 lefties showed 40 had heart problems. While 500 righties showed 30 had heart problems. Is this difference significant at a 5% level to show there is a difference between righties and lefties?
Mathematics - 2 Answers
Random Answers, Critics, Comments, Opinions :
1 :
No, since the two samples are not equally-representative of their respective populations
2 :
We should perform a test of hypothesis. Let P1 be the population proportion of lefties have heart diseases P2 be the population proportion of righties have heart diseases. The appropriate hypotheses are: H0: P1 <= P2 H1: P1 > P2. Now let p1 and p2 be the sample proportion of lefties and righties have heart diseases, respectively. Here p1=40/500 and p2=30/500. We reject H0 (accept H1) if and only if: (p1-p2)/s > z, where s = ( p(1-p)*(1/n1+1/n2) )^1/2 ; p=(m1+m2)/(n1+n2), m1=40, m2=30, n1=n2=500, z = -1.64 (0.05-percentile of standard normal distribution). I leave the computations to you!
Read more discussions :
- * Is there a connection between gum disease and he...
- What are some general things that help prevent hea...
- How does dietary fibre decrease risk of coronory h...
- What does the fact that triglycerides are nonpolar...
- How can I ease my worries? my six month old son ha...
- Obesity, High Blood Pressure, and Stress create th...
- what culturql factors might predispose a Polish Am...
- Does an echocardiogram show all types of heart dis...
