A researcher wishes to estimate, with 95% confidence, the population proportion of motor vehicle fatalities that were caused by alcohol-impaired driving. His estimate must be accurate within 2% of the population 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 32% of motor vehicle fatalities that were caused by alcohol-impaired driving. (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 32% of motor vehicle fatalities that were caused by alcohol-impaired driving? (Round up to the nearest whole number as needed.) n= (c) How do the results from (a) and (b) compare? O A. Having an estimate of the population proportion reduces the minimum sample size needed. O B. Having an estimate of the population proportion raises the minimum sample size needed. OC. Having an estimate of the population proportion has no effect on the minimum sample size needed.

A researcher wishes to estimate, with 99% confidence, the population proportion of motor vehicle fatalities that were caused by alcohol-impaired driving. His estimate must be accurate within 5% of the population 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 36% of motor vehicle fatalities that were caused by alcohol-impaired driving. (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 36% of motor vehicle fatalities that were caused by alcohol-impaired driving? n=(Round up to the nearest whole number as needed.) (c) How do the results from (a) and (b) compare? OA. Having an estimate of the population proportion has no effect on the minimum sample size…

You work for a marketing firm that has a large client in the automobile industry. You have been asked to estimate the proportion of households in Chicago that have two or more vehicles.  You have been assigned to gather a random sample that could be used to estimate this proportion to within a 0.02 margin of error at a 90% level of confidence. a)  With no prior research, what sample size should you gather in order to obtain a 0.02 margin of error? Round your answer up to the nearest whole number. n =  households b)  Your firm has decided that your plan is too expensive, and they wish to reduce the sample size required. You conduct a small preliminary sample, and you obtain a sample proportion of ˆp=0.22p^=0.22 . Using this new information. what sample size should you gather in order to obtain a 0.02 margin of error? Round your answer up to the nearest whole number. n =  households

In a study of government financial aid for college students, it becomes necessary to estimate the percentage of full-time college students who earn a bachelor's degree in four years or less. Find the sample size needed to estimate that percentage. Use a 0.02 margin of error and use a confidence level of 95%. Complete parts (a) through (c) below. a. Assume that nothing is known about the percentage to be estimated. (Round up to the nearest integer.) b. Assume prior studies have shown that about 40% of full-time students earn bachelor's degrees in four years or less. (Round up to the nearest integer.) c. Does the added knowledge in part (b) have much of an effect on the sample size? O A. Yes, using the additional survey information from part (b) dramatically reduces the sample size. O B. No, using the additional survey information from part (b) only slightly reduces the sample size. O C. Yes, using the additional survey information from part (b) only slightly increases the sample size. O…