A medical researcher is interested in determining if there is a relationship between adults over 50 who walk regularly and low, moderate, and high blood pressure. A random sample of 236 adults over 50 is selected and results are given below.
Blood
Pressure Adults over 50
Walkers Non-walkers
Low 35 21
Moderate
62 65
High 25 28
a. From the contingency table, the researcher concluded that there is relationship between adults over 50 who walk regularly and low, moderate, and high blood pressure.
Do you agree? Test using .
b. Construct a 95% confidence interval for the true percentage of walkers with low blood pressure. Is the sample size large enough to construct a valid confidence interval for p?
c. How large a sample size is necessary to estimate the proportion of walkers with low blood pressure within 10% with 95% confidence?