8.EOC.56-E Question Help V 0 According to the Bureau of Labor Statistics, the average hourly wage in the United States was $26.84 in April 2018. To conrm this wage, a random sample of 39 hourly workers was selected during the month. The average wage for this sample was $25.14. Assume the standard deviation of wages for the country is $4.25. Complete parts a and b. a. Are the results of this sample consistent with the claim made by the Bureau of Labor Statistics using a 95% condence interval? The condence interval is $ sxs$ . The Bureau's claim (Round to two decimal places as needed.) v between the lower limit and the upper limit of the condence interval, so the results of the sample consistent with the claim. 8.EOC.57-E Question Help V at A sports league introduced a video referee to review certain critical plays. However, the system has not been without its controversies. One particular unfortunate incident led to an outcry among fans. Nevertheless, a poll alter this event found that 62% of fans were still in favor of the continued use of the video referee. Suppose the size of this sample was 600 people. Complete parts a and b. a. Estimate the true proportion of fans in favor of keeping the video referee using a 95% condence interval. The condence interval has a lower limit of (Round to three decimal places as needed.) and an upper limit of 8.EOC.58-E Question Help According to a government agency, 53.8% of mothers in a certain region were breast-feeding their nine-month-old babies in 2016. Suppose a health insurance company would like to estimate the proportion of mothers in the region who breast-fed their children at nine months in 2018. A random sample of 240 mothers with nine-month-old babies was selected, 145 of which were breast-feeding. Complete parts a through c. a. Construct a 90% confidence interval to estimate the actual proportion of mothers with nine-month-old babies that were breast-feeding in 2018. The confidence interval has a lower limit of | and an upper limit of]. (Round to three decimal places as needed.)8..E0059-E Question Help V at The following data show the costs charged by a tax preparation service for a random sample of 15 tax returns. Complete parts a through c. $130 $115 $125 $205 $95 :11 $125 $95 $200 $145 $75 $155 $115 $185 $155 $65 3. Using a 95% condence interval, estimate the average cost of the service for preparing a tax return for a customer. The 95% condence interval is from $ to $ I. (Round to two decimal places as needed. Use ascending order.) 8..EOC63-E Question HelpV at Certain advertisers would like to estimate the proportion of viewers who spend the majority of their television time watching alone, The consensus is that this percentage has been increasing over the years due to the increased number of television sets in households. a. Determine the sample size needed to construct a 98% condence interval with a margin of error of no more than 5% to estimate the true proportion of viewers who watch television alone. b. What impact would a pilot sample that showed that 41% of viewers spend the majority of their television time watching alone have on your results. a. The sample size needed is . (Round up to the nearest integer.) 8.EOC.64-E Question Help A governmental department would like to estimate the average weekly wages for adults with a margin of error equal to $18. Determine the sample sizes needed to construct a confidence interval for this estimate using the following confidence levels. Assume the population standard deviation for the weekly wage is $160. a. 90% b. 98% c. 99% d. Explain why the confidence level affects the sample size needed to obtain a particular margin of error.8.EOC.66-E Question Help Your school claims that the average student graduates with debt of $1,750. To validate this claim, you create a random sample of 20 students during graduation and ask each student to anonymously report the amount of their student loan debt. Complete parts a through c. $0 $0 $3 $300 $1,000 $0 $1,900 $2,250 $2,900 $1,900 $0 $2,200 $2,200 $3, 100 $2,800 $0 $2, 100 $350 $2,350 $2,850 a. Construct a 95% confidence interval with these data to estimate the average student loan debt of students graduating at your school. The 95% confidence interval is from $ to $]. (Round to two decimal places as needed. Use ascending order.)8.EOC.67-E Question Help A cell phone company would like to estimate the average number of text messages received by American teenagers per month. A random sample of 53 teenaged customers was selected. The sample average was 2,249 messages per month, and the sample standard deviation was 962 messages per month. Construct confidence intervals with the given confidence levels. a. 90% b. 95% C. 99%8.EOC.69-E Question Help A government bureau would like to estimate the average annual contributions to charity by the members of Generation Y (people born in the United States in the years 1981 through 1991). The following data show the annual contributions to charity for a random sample of 18 individuals in this age group. Complete parts a and b. $20 $750 $390 $160 $195 $515 0 $270 $420 $445 $192 $460 $330 $60 $595 $405 $160 $655 $220 a. Construct a 90% confidence interval with these data to estimate the average annual contributions to charity for this age group. The 90% confidence interval is from $ to $. (Round to two decimal places as needed. Use ascending order.)8.EOC.70-E Question Help According to recent data by the American Marketing Association, 76.5% of people in the 18-24 age group used social media in 2017. You want to find out what the social media proportion is among your classmates who are all between 18 and 24 years old. Suppose you obtain a random sample of 231 students and find that 207 students in this sample are active social media users. Complete parts a through c below. a. Construct a 90% confidence interval to estimate the actual proportion of social media users. A 90% confidence interval to estimate the actual proportion has a lower limit of and an upper limit of ]. (Round to three decimal places as needed.)8.EOC.71-E Question HelpV '0 At its peak after the 20072008 recession, credit card delinquency rates in a certain region reached 10.02%, Since its peak, delinquency rates have declined to a new low of 5.41% in the second quarter of 2015, You are charged with checking the most recent credit card delinquency rates in the region, Using a random sample of 449 credit card customers, you found that 28 were at least 30 days overdue on their monthly payments. Using a 90% condence interval, can you conclude that the proportion of delinquent card holders changed since its lowest point in 2015? The 90% condence interval to estimate the actual most recent proportion of delinquent card holders has a lower limit of (Round to three decimal places as needed.) and an upper limit of 8.EOC.73-E Question Help Using a 90% confidence level, a governmental department would like to estimate the average weekly hours worked by private employees in the country who are adults. Assume the standard deviation for the number of hours worked is seven hours. Determine the sample sizes needed to construct this confidence interval using the following margins of error. a. 3 hours b. 2 hours c. 30 minutes d. Explain why the margin of error affects the sample size needed to obtain a particular confidence level