1.

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 4% 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.)Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 3428 adults in a country, 49% believe the economy is getting better. Three weeks prior to this survey, 51% believed that the economy was getting better. The survey's margin of error is + 1%. Use the results from the newer survey. The confidence interval for the proportion is ( ) (Round to three decimal places as needed.)State Ho Ind Ha in words and in symbols. Then determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. EprIin your reasoning. Sketch a normal sampling distribution and shIde the area for the Pvalue. A reporl claims that. lung cancer accounts for at least 21% of all cancer diagnoses. State the null hypothesis in words Ind in symbols. The null hypothesis expressed in words is the proportion of cancer diagnoses attributable to lung cancer E I]. The null hypothesis is expressed symbolically as H": pa I]. (Type integers or decimals. Do not round.) - - is not. # is at most 2 is > is at least 5 is h$ than