Question

In: Statistics and Probability

A medical researcher wants to construct a 99% confidence interval for the proportion of knee replacement...

A medical researcher wants to construct a 99% confidence interval for the proportion of knee replacement surgeries that result in complications. An article in the Journal of Bone and Joint Surgery suggested that approximately 8% of such operations result in complications. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.047 ? Write only an integer as your answer.

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Expert Solution

Sample size estimation for proportion                              
                              
Preliminary estimate for proportion (Known) =    0.08          
Margin of error =E=0.047          
Level of significance =1-0.99=   0.01          
Z critical value is (by using Z table)=2.58          
                              
Sample size


=221.06

Therefore, sample size approximately will be 222
                           


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