1.A simple random sample of 400 individuals provides 100 Yes responses.
a. What is the point estimate of the proportion of the population that would provide Yes
responses?
b. What is your estimate of the standard error of the proportion, ?
c. Compute the 95% confidence interval for the population proportion.32.
2. A simple random sample of 800 elements generates a sample proportion .70.
a. Provide a 90% confidence interval for the population proportion.
b. Provide a 95% confidence interval for the population proportion.
3. In a survey, the planning value for the population proportion is p* .35. How large a
sample should be taken to provide a 95% confidence interval with a margin of error of .05?
4. At 95% confidence, how large a sample should be taken to obtain a margin of error of .03
for the estimation of a population proportion? Assume that past data are not available for
developing a planning value for p*.
