wikiHow Calculating Sample Size Practice Problems Note: The required sample size for each practice problem depends on the specific values used for the variables in the sample size formula, and may vary from one problem to another. 1. A researcher wants to determine the proportion of people in a city who have a certain disease with a 99% confidence level and a margin of error of 0.02. If the estimated proportion of people with the disease is 0.05, what is the required sample size? 2. A company wants to estimate the average income of its employees with a 95% confidence level and a margin of error of $100. If the standard deviation of employee income is $500, what is the required sample size? 3. A political campaign wants to estimate the proportion of voters who support their candidate with a 90% confidence level and a margin of error of 0.03. If they have no estimate of the proportion of supporters, what is the required sample size? 4. A hospital wants to estimate the proportion of patients who are satisfied with their care with a 95% confidence level and a margin of error of 0.05. If they have no estimate of the proportion of satisfied patients, what is the required sample size? 5. A school wants to estimate the proportion of students who will attend a summer program with a 90% confidence level and a margin of error of 0.02. If they estimate that 50% of students will attend the program, what is the required sample size? 6. A survey wants to estimate the proportion of people who support a new policy with a 95% confidence level and a margin of error of 0.01. If a previous survey estimated the proportion to be 0.6, what is the required sample size? 7. A researcher wants to estimate the proportion of drivers who use their phones while driving with a 99% confidence level and a margin of error of 0.03. If the estimated proportion is 0.1, what is the required sample size? 8. A business wants to estimate the proportion of customers who are satisfied with their service with a 95% confidence level and a margin of error of 0.05. If the estimated proportion is 0.8, what is the required sample size? 9. A study wants to estimate the proportion of patients who experience side effects from a medication with a 90% confidence level and a margin of error of 0.02. If the estimated proportion is 0.2, what is the required sample size? 10. A researcher wants to estimate the average height of a population with a 95% confidence level and a margin of error of 2 inches. If the standard deviation of height is 3 inches, what is the required sample size? 11. A charity wants to estimate the proportion of people who will donate to their cause with a 90% confidence level and a margin of error of 0.05. If they estimate that 20% of people will donate, what is the required sample size? 12. A company wants to estimate the proportion of people who will buy a new product with a 99% confidence level and a margin of error of 0.01. If a previous survey estimated the proportion to be 0.3, what is the required sample size? 13. A study wants to estimate the proportion of people who are vegetarian with a 95% confidence level and a margin of error of 0.02. If a previous study estimated the proportion to be 0.1, what is the required sample size? 14. A researcher wants to estimate the proportion of people who exercise regularly with a 90% confidence level and a margin of error of 0.05. If the estimated proportion is 0.7, what is the required sample size? 15. A study wants to estimate the proportion of people who own a car with a 95% confidence level and a margin of error of 0.03. If a previous study estimated the proportion to be 0.6, what is the required sample size? 16. A company wants to estimate the average time it takes to complete a task with a 90% confidence level and a margin of error of 5 minutes. If the standard deviation of completion time is 15 minutes, what is the required sample size? 17. A study wants to estimate the proportion of people who have a specific genetic trait with a 95% confidence level and a margin of error of 0.02. If a previous study estimated the proportion to be 0.4, what is the required sample size? 18. A researcher wants to estimate the proportion of people who prefer a certain brand of soda with a 99% confidence level and a margin of error of 0.03. If the estimated proportion is 0.2, what is the required sample size? 19. A company wants to estimate the proportion of customers who would recommend their product with a 95% confidence level and a margin of error of 0.05. If the estimated proportion is 0.85, what is the required sample size? 20. A study wants to estimate the proportion of people who use public transportation with a 90% confidence level and a margin of error of 0.02. If a previous study estimated the proportion to be 0.3, what is the required sample size? Page