# An investigator wants to estimate the impact of smoking on the incidence of prostate cancer. The incidence of prostate cancer by the age of 70 is about 1 in 6 (17%) P2=0.17. U.S. study reporters that heavy smokers had twice the risk of developing prostate cancer as compared to nonsmokers (34%) P1=0.34. A repeat study in England, cohort enrolls men at age 50 and followed them for 30 years. Problem: Generste a 95% confidence level, assume a 20% attrition, and a margin of error of no more than 0.05 (5%) E=0.05

Question

An investigator wants to estimate the impact of smoking on the incidence of prostate cancer. The incidence of prostate cancer by the age of 70 is about 1 in 6 (17%) P2=0.17. U.S. study reporters that heavy smokers had twice the risk of developing prostate cancer as compared to nonsmokers (34%) P1=0.34. A repeat study in England, cohort enrolls men at age 50 and followed them for 30 years.

Problem: Generste a 95% confidence level, assume a 20% attrition, and a margin of error of no more than 0.05 (5%) E=0.05

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Step 1

Note:

Hi there! Thanks for posting the question. It is not clear from your question that what to calculate. Based on the given information we understand that we have compute the number of individuals would needed for the experiment and the number of individuals would be needed to account for 20% attrition.

Step 2

Preliminary information:

Proportion of success in group 1 is p1 is 0.34.

Proportion of success in group 2 is p2 is 0.17.

Margin of error, E=0.05

Using the EXCEL formula “=NORM.S.INV(1-(0.05/2))”, the z-value for 95% confidence level is obtained as 1.96.

Step 3

Computation of number of individuals would needed:

The number of individuals would need to be included in sample 1 and sample 2 are obtaine...

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