A researcher wishes to estimate, with 99% confidence, the population proportion of adults who think Congress is doing a good or excellent job. Her estimate must be accurate within 3% of the true proportion. (a) No preliminary estimate is available. Find the minimum sample size needed. (b) Find the minimum sample size needed, using a prior study that found that 34% of the respondents said they think Congress is doing a good or excellent job. (c) Compare the results from parts (a) and (b).

You are doing a research project in political science to determine the proportion of voters in your district who favor capital punishment. a. If no preliminary sample of voters is taken to estimate p, how large a sample is necessary to be 99% sure that the point estimate will be within a distance of .01 from p? b. The NORC found that approximately 67% of people in the U.S. favor capital punishment. How large a sample is necessary to be 99% sure that the point estimate will be within a distance of .01 from p?

A programmer plans to develop a new software system. In planning for the operating system that he will use, he needs to estimate the percentage of computers that use a new operating system. How many computers must be surveyed in order to be 90% confident that his estimate is in error by no more than three percentage points? Complete parts (a) through (c) below. a) Assume that nothing is known about the percentage of computers with new operating systems. n = (Round up to the nearest integer.) b) Assume that a recent survey suggests that about 98% of computers use a new operating system. n= (Round up to the nearest integer.) c) Does the additional survey information from part (b) have much of an effect on the sample size that is required? O A. Yes, using the additional survey information from part (b) dramatically increases the sample size. O B. No, using the additional survey information from part (b) only slightly increases the sample size. OC. No, using the additional survey…

A researcher wishes to​ estimate, with 90% ​confidence, the population proportion of adults who think Congress is doing a good or excellent job. Her estimate must be accurate within 2% of the true proportion. ​(A) No preliminary estimate is available. Find the minimum sample size needed. (Round up to the nearest whole number as​needed.)