Question

The anterior cruciate ligament (ACL) runs diagonally in the middle of the knee. An article reported results for 85 young athletes who suffered anterior cruciate ligament (ACL) injuries. Of the 85 injuries, 55 were to the left knee and 30 were to the right knee. Can you conclude that more than half of ACL injuries are to the left knee? Find the P-value and state a conclusion. The P-value is We (Click to select) conclude that more than half of ACL injuries are to the left knee.

Answer 1

Below are the null and alternative Hypothesis,
Null Hypothesis, H0: p = 0.5
Alternative Hypothesis, Ha: p > 0.5

Test statistic,
z = (pcap - p)/sqrt(p*(1-p)/n)
z = (0.6471 - 0.5)/sqrt(0.5*(1-0.5)/85)
z = 2.71

P-value Approach
P-value = 0.0034
As P-value < 0.04, reject the null hypothesis.

we can conclude that more than half of ACL are to the left nee