STATE: Which type of fast‑food chain fills orders most accurately at the drive‑thru window? The Quick Service Restaurant (QSR) magazine drive‑thru study visits restaurants in the largest fast‑food chains in all 50 states. Visits occurred throughout the day, starting at 5:00 A.M and ending at 7:00 P.M. During each visit, the researcher ordered a main item, a side item, and a drink and made a minor special request such as a beverage with no ice. After receiving the order, all food and drink items were checked for complete accuracy. Any food or drink item received that was not exactly as ordered resulted in the order being classified as inaccurate. Also included in the measurement of accuracy were condiments asked for, napkins, straws, and correct change. Any errors in these resulted in the order being classified as innacurate. In 2019, Arby's, Burger King, Carl's Jr., Chick-fil-A, Dunkin', Hardee's, KFC, McDonald's, Taco Bell, and Wendy's were included in the study. KFC had the most inaccuracies, with 56 of 165 orders classified as inaccurate. What proportion of orders are filled accurately by KFC? (Use 95% confidence.) Determine a 95% confidence interval for the population proportion of orders that are filled accurately by KFC. Give your answer as an interval in the form (lower bound,upper bound). Give the bounds to four decimal places. Enter DNE if the conditions are not met.
STATE: Which type of fast‑food chain fills orders most accurately at the drive‑thru window? The Quick Service Restaurant (QSR) magazine drive‑thru study visits restaurants in the largest fast‑food chains in all 50 states. Visits occurred throughout the day, starting at 5:00 A.M and ending at 7:00 P.M. During each visit, the researcher ordered a main item, a side item, and a drink and made a minor special request such as a beverage with no ice. After receiving the order, all food and drink items were checked for complete accuracy. Any food or drink item received that was not exactly as ordered resulted in the order being classified as inaccurate. Also included in the measurement of accuracy were condiments asked for, napkins, straws, and correct change. Any errors in these resulted in the order being classified as innacurate.
In 2019, Arby's, Burger King, Carl's Jr., Chick-fil-A, Dunkin', Hardee's, KFC, McDonald's, Taco Bell, and Wendy's were included in the study. KFC had the most inaccuracies, with 56 of 165 orders classified as inaccurate. What proportion of orders are filled accurately by KFC? (Use 95% confidence.)
Determine a 95% confidence interval for the population proportion of orders that are filled accurately by KFC. Give your answer as an interval in the form (lower bound,upper bound). Give the bounds to four decimal places. Enter DNE if the conditions are not met.
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