Statistics Ch 7 Exam - Questions and Answers A newspaper provided a "snapshot" illustrating poll results from 1910 professionals who interview job
... [Show More] applicants. The illustration showed that 26% of them said the biggest interview turnoff is that the applicant did not make an effort to learn about the job or the company. The margin of error was given as plus or minus 3 percentage points. What important feature of the poll was omitted? The confidence leve A magazine provided results from a poll of 1000 adults who were asked to identify their favorite pie. Among the 1000 respondents, 13% chose chocolate pie, and the margin of error was given as plus or minus3 percentage points. Given specific sample data, which confidence interval is wider: the 95% confidence interval or the 80% confidence interval? Why is it wider? A 95% confidence interval must be wider than an 80% confidence interval in order to be more confident that it captures the true value of the population proportion. Express the confidence interval 0.444less thanpless than0.666 in the form ModifyingAbove p with caret plus or minus Upper E. p+-e ____+-_______ 0.444+0.666 / 2 then .666-.444 /2 Express the confidence interval left parenthesis 0.026 comma 0.120 right parenthesis in the form of ModifyingAbove p with caret minus Upper E less than p less than ModifyingAbove p with caret plus Upper E. lower number first < p < higher A magazine provided results from a poll of 1000 adults who were asked to identify their favorite pie. Among the 1000 respondents, 11% chose chocolate pie, and the margin of error was given as plus or minus4 percentage points. Describe what is meant by the statement that "the margin of error was given as plus or minus4 percentage points." The statement indicates that the interval 11%plus or minus4% is likely to contain the true population percentage of people that prefer chocolate pie. A magazine provided results from a poll of 500 adults who were asked to identify their favorite pie. Among the 500 respondents, 11% chose chocolate pie, and the margin of error was given as plus or minus3 percentage points. What values do ModifyingAbove p with caret, ModifyingAbove q with caret, n, E, and p represent? If the confidence level is 99%, what is the value of alpha? f the confidence level is 99%, what is the value of alpha? The value of p with caret is the sample proportion. The value of q with caret is found from evaluating 1 minus p with caret . The value of n is the sample size. The value of E is the margin of error. The value of p is the population proportion. f the confidence level is 99%, what is the value of alpha? a=0.01 Find the critical value z Subscript alpha divided by 2 that corresponds to the given confidence level. 83% 1-.83 .17 /2 .085 invnorm(.085,0,1) 1.37 (no negative) Find the critical value z Subscript alpha divided by 2 that corresponds to the confidence level 83%. 1-.83 .17/2 1-.085=.915 invnorm(.915,0,1) 1.37 According to the Rule of Three, when we have a sample size n with xequals0 successes, we have 95% confidence that the true population proportion has an upper bound of StartFraction 3 Over n EndFraction . a. If n independent trials result in no successes, why can't we find confidence interval limits by using the methods described in this section? b. If 40 couples use a method of gender selection and each couple has a baby girl, what is the 95% upper bound for p, the proportion of all babies who are boys? The requirement of at least 5 successes and at least 5 failures is not satisfied, so the normal distribution cannot be used. b. The 95% upper bound for p, the proportion of all babies who are boys, is 0.075. A critical value, z Subscript alpha, denotes the _______. z dash score with an area of alpha to its right. Which concept below is NOT a main idea of estimating a population proportion? Using a sample statistic to estimate the population proportion is utilizing descriptive statistics. Which of the following groups has terms that can be used interchangeably with the others? Percentage, Probability, and Proportion A _______ is a single value used to approximate a population parameter. point estimate Which of the following is NOT an observation about [Show Less]