Suppose that a market research firm is hired to estimate the percent of adults living in a large city who have cell phones. 500 randomly selected adult residents in this city are surveyed to determine whether they have cell phones. Of the 500 people surveyed, 421 responded yes – they own cell phones. a) Using a 90% confidence level, compute a confidence interval estimate for the percentage of all adults in this large city who have cell phones. b) Using the sample data, what is the minimum sample size needed so that the margin of error in a 90% confidence interval is less than 0.01?

In a random sample of 400 adults in a small town, 189 of them participated in some form of adult education. Find a 98% confidence interval for the population proportion of adults in the town who participate in adult education

You recently sent out a survey to determine if the percentage of adults who use social media has changed from 62%, which was the percentage of adults who used social media five years ago. Of the 2283 people who responded to survey, 1635 stated that they currently use social media.a) Use the data from this survey to construct a 94% confidence interval estimate of the proportion of adults who use social media. Record the result below in the form of (#,#)(#,#). Round your final answer to four decimal places.

In a survey of 2101 adults in a recent​ year, 1366 say they have made a New​ Year's resolution.Construct​ 90% and​ 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals

You recently sent out a survey to determine if the percentage of adults who use social media has changed from 58%, which was the percentage of adults who used social media five years ago. Of the 2670 people who responded to survey, 1767 stated that they currently use social media. a) Use the data from this survey to construct a 93% confidence interval estimate of the proportion of adults who use social media. Record the result below in the form of (#, #). Round your final answer to four decimal places.

In a survey of 2569 adults in a recent​ year, 1303 say they have made a New​ Year's resolution. Construct​ 90% and​ 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals.

Alicia would like to know if there is a difference in the average price between two brands of shoes. She selected and analyzed a random sample of 40 different types of Brand A shoes and 33 different types of Brand B shoes. Alicia observes that the boxplot of the sample of Brand A shoe prices shows two outliers. Alicia wants to construct a confidence interval to estimate the difference in population means. Is the sampling distribution of the difference in sample means approximately normal? A) Yes, because Alicia selected a random sample. B) Yes, because for each brand it is reasonable to assume that the population size is greater than ten times its sample size. C) Yes, because the size of each sample is at least 30. D) No, because the distribution of Brand A shoes has outliers. E) No, because the shape of the population distribution is unknown.

In a survey of 3500 ​adults, 1443 say they have started paying bills online in the last year.   Construct a​ 99% confidence interval for the population proportion. Interpret the results.

A survey of 2316 adults in a certain large country aged 18 and older conducted by a reputable polling organization found that 424 have donated blood in the past two years. a.) obtain a point estimate for the population proportion of adults in the country aged 18 and older who have donated blood in the past two years  b.) Construct and interpret a 90% confidence interval for the population proportion of adults in the country who have donated blood in the past two years. Select the correct choice below. We are ? % confident the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between ? and ? or There is a ?% probability the proportion of adults in the country aged 18 and older who have donated blood in the past two years is between ? and ?

The National Research center conducted a survey of 1000 people to learn about their major international concern.  The survey results showed that 760 of the respondents indicated computer cyber attacks is their major international concern.  Develop a 94% confidence interval for the population proportion of adults who think computer cyber attacks is their major international concern.