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 within2% 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 46% of the respondents said they think Congress is doing a good oeexcellent job. (c) compare the results from a parts (a) and (b). (A) what is the minimum sample size needed assuming that no prior information is available? Round to the nearest whole number as needed.

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 33​% 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 38​% of the respondents said they think Congress is doing a good or excellent job. ​(c) Compare the results from parts​ (a) and​ (b).     ​(a) What is the minimum sample size needed assuming that no prior information is​ available? N= ​(Round up to the nearest whole number as​ needed.)   ​(b) What is the minimum sample size needed using a prior study that found that 38​% of the respondents said they think Congress is doing a good or excellent​ job? N= ​(Round up to the nearest whole number as​ needed.)   ​(c) How do the results from ​(a) and ​(b)​ compare? A. Having an estimate of the population proportion has no…

A researcher wishes to​ estimate, with 95​% ​confidence, the population proportion of adults who support labeling legislation for genetically modified organisms​ (GMOs). Her estimate must be accurate within 5​% 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 81​% of the respondents said they support labeling legislation for GMOs. ​(c) Compare the results from parts​ (a) and​ (b).

You have been asked to estimate the proportion of households in Chicago that have two or more vehicles.   a) How many households would you need to sample to be within 2 percent of the proportion of all households in Chicago that have two or more vehicles at a 90% level of confidence.     b) You conduct a small preliminary sample, and you obtain a sample proportion of 19.5% that have two or more cars. Using this new information, what sample size should you gather in order to be within 2 percent of the proportion of all households in Chicago that have two or more vehicles at a 90% level of confidence.