where p is the proportion of adult residents in the city who are able to pass the physical fitness test.
The Recreation Department recruits 185 residents who volunteer to take the physical fitness test. The test is passed by 77 of the 185 volunteers, indicating that more than 35 percent of the city is in shape. Describe the primary flaw in the study described in part and explain why it is a concern.
The primary flaw is that the sample will slightly overestimate the physical fitness of the people of the town.
The given hypothesis are,
Type II error is accepted in null hypothesis when it is not actually true.
In the given question null hypothesis p= 0.35
The conclusion is that in the given sample proportion is not equal to 0.35, though we know that proportion is not equal to 0.35 we accept the null hypothesis, that is wrong.
Now given n=185,x=77 P=0.53 then Q=1-0.35=0.65
Now test statistic
Solving for Z using the given values we get :
So we accept
The primary flaw in the system is that the sample is not randomly selected rather they are volunteers. So it is reasonable to think that the physical fitness of the town will be slightly over estimated by the experiment.
To learn more about sample of an experiment: