MATH 225N Week 6 Assignment Understanding Confidence Intervals – Excel

MATH 225N Week 6 Assignment: Understanding Confidence Intervals – Excel

1. Question: In a random sample of 350 attendees of a minor league baseball game, 184 said that they bought food from the concession stand. Create a 95% confidence interval for the proportion of fans who bought food from the concession stand. Use Excel to create the confidence interval, rounding to four decimal places.
2. Question: In a survey of 603 adults, 98 said that they regularly lie to people conducting surveys. Create a 99% confidence interval for the proportion of adults who regularly lie to people conducting surveys. Use Excel to create the confidence interval, rounding to four decimal places.
3. Question: A sample of 22test-tubes … for number of times they can … on a Bunsen burner before they crack is … Assume the counts are normally distributed. Use Excel to construct a 99% confidence interval for μ. Round your answers to two decimal places and use increasing order.
4. Question: A company wants to determine a confidence interval for the average CPU time of its teleprocessing transactions. A sample of 70random transactions in milliseconds is … below. Assume that the transaction times follow a normal distribution with a standard deviation of 600 milliseconds. Use Excel to determine a 98% confidence interval for the average CPU time in milliseconds. Round your answers to the nearest integer and use ascending order.
5. Question: Weights, in pounds, of ten-year-old girls are … from a neighborhood. A sample of 26 is given below. Assuming normality, use Excel to find the 98% confidence interval for the population mean weight μ. Round your answers to three decimal places and use increasing order.
6. Question: The monthly incomes from a random sample of 20 workers in a factory is given below in dollars. Assume the population has a normal distribution and has standard deviation $518. Compute a 98%confidence interval for the mean of the population. Round your answers to the nearest dollar and use ascending order.
7. Question: In a survey of 1,000 adults in a country, 722 said that they had eaten fast food at least once in the past month. Create a 95% confidence interval for the population proportion of adults who ate fast food at least once in the past month. Use Excel to create the confidence interval, rounding to four decimal places.
8. Question: A city is holding a referendum on increasing property taxes to pay for a new high school. In a survey of 458 likely voters, 254 said that they would vote “yes” on the referendum. Create a 95% confidence interval for the proportion of likely voters who will vote “yes” on the referendum. Use Excel to create the confidence interval, rounding to four decimal places.
9. Question: The yearly incomes, in thousands, for 24 random … couples living in a city are given below. Assume the yearly incomes are approximately normally … Use Excel to find the 95%confidence interval for the true mean, in thousands. Round your answers to three decimal places and use increasing order.
10. Question: In a city, 22 coffee shops are randomly …, and the temperature of the coffee sold at each shop is … Use Excel to find the 90% confidence interval for the population mean temperature. Assume the temperatures are approximately normally distributed. Round your answers to two decimal places and use increasing order.
11. Question: Suppose the weights of tight ends in a football league are normally … such that σ₂=1,369. A sample of 49tight ends was randomly … , and the weights are … Use Excel to calculate the 95% confidence interval for the mean weight of all tight ends in this league. Round your answers to two decimal places and use ascending order.
12. Question: The following data represent a sample of the assets (in millions of dollars) of 28 credit unions in a state. Assume that the population in this state is normally … with σ=3.5 million dollars. Use Excel to find the 99% confidence interval of the mean assets in millions of dollars. Round your answers to three decimal places and use ascending order.
    

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MATH 225N Week 6 Assignment: Understanding Confidence Intervals – Excel

1. Question: In a random sample of 350 attendees of a minor league baseball game, 184 said that they bought food from the concession stand. Create a 95% confidence interval for the proportion of fans who bought food from the concession stand. Use Excel to create the confidence interval, rounding to four decimal places.
2. Question: Alison, the owner of a regional chain of pizza stores, is trying to decide whether to add calzones to the menu. She conducts a survey of700 people in the region and asks whether they would order calzones if they were on the menu. 46 people … “yes.” Create a 90% confidence interval for the proportion of people in the region who would order calzones if they were on the menu. Round your answer to four decimal places. 
3. Question: A company wants to determine a confidence interval for the average CPU time of its teleprocessing transactions. A sample of70 random transactions in milliseconds is given below. Assume that the transaction times follow a normal distribution with a standard deviation of 600  Use Excel to determine a 98% confidence interval for the average CPU time in milliseconds. Round your answers to the nearest integer and use ascending order.
4. Question: Suppose the weights of tight ends in a football league are … such thatσ2=1,369. A sample of 49 tight ends was randomly …, and the weights are given below. Use Excel to calculate the 95% confidence interval for the mean weight of all tight ends
5. Question: A sample of 22 test-tubes … for number of times they can … on a Bunsen burner before they crack is given below. Assume the counts are … Use Excel to construct a 99% confidence interval for μ. Round your answers to two decimal places and use increasing order.
6. Question: A tax assessor wants to assess the mean property tax bill for all homeowners in a certain state. From a survey ten years ago, a sample of28 property tax bills is given below. Assume the property tax bills are approximately … Use Excel to construct a 95% confidence interval for the population mean property tax bill. Round your answers to two decimal places and use increasing order.
7. Question: The following data represent a sample of the assets (in millions of dollars) of28 credit unions in a state. Assume that the population in this state is … with σ=5 million dollars. Use Excel to find the 99% confidence interval of the mean assets in millions of dollars. Round your answers to three decimal places and use ascending order.
8. Question: A study was … to estimate the mean age when people buy their first new car. The ages of purchase for 22randomly … Assume the ages are approximately … Use Excel to determine the99% confidence interval for the mean. Round your answers to two decimal places and use increasing order.
9. Question: In a random sample of2,282 college students, 356 … getting 8 or more hours of sleep per night. Create a 95%confidence interval for the proportion of college students who get 8 or more hours of sleep per night. Use Excel to create the confidence interval, rounding to four decimal places.
10. Question: A restaurant is reviewing customer complaints. In a sample of227 complaints, 57 complaints were about the slow speed of the service. Create a 95% confidence interval for the proportion of complaints that were about the slow speed of the service. Use Excel to create the confidence interval, rounding to four decimal places.
11. Question: The monthly incomes from a random sample of20 workers in a factory is given below in dollars. Assume the population has a normal distribution and has standard deviation $518. Compute a 98% confidence interval for the mean of the population. Round your answers to the nearest dollar and use ascending order.
12. Question: The number of hours … per year per adult in a state is normally … with a standard deviation of37. A sample of 115 adults is … at random, and the number of hours … per year per adult is … Use Excel to calculate the 98% confidence interval for the mean hours … per year for adults in this state. Round your answers to two decimal places and use ascending order.
13. Question: A type of golf ball is … by dropping it onto a hard surface from a height of1  The height it bounces is … A sample of 25 balls is … and the bounce heights are … below. Use Excel to find a 95% confidence interval for the mean bounce height of the golf ball. Round your answers to two decimal places and use increasing order.
14. Question: A college admissions director wishes to estimate the mean age of all students currently enrolled. The age of a random sample of23 students is …. Assume the ages are approximately … Use Excel to construct a 90% confidence interval for the population mean age. Round your answers to two decimal places and use increasing order.
15. Question: Weights, in pounds, of ten-year-old girls are … from a neighborhood. A sample of26 is given below. Assuming normality, use Excel to find the 98% confidence interval for the population mean weight μ. Round your answers to three decimal places and use increasing order.
    

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MATH 225N Week 6 Assignment: Understanding Confidence Intervals – Excel

1. Question: In a random sample of 350 attendees of a minor league baseball game, 184 said that they bought food from the concession stand. Create a 95% confidence interval for the proportion of fans who bought food from the concession stand. Use Excel to create the confidence interval, rounding to four decimal places.
2. Question: Alison, the owner of a regional chain of pizza stores, is trying to decide whether to add calzones to the menu. She conducts a survey of 700 people in the region and asks whether they would order calzones if they were on the menu. 46 people … “yes.” Create a 90% confidence interval for the proportion of people in the region who would order calzones if they were on the menu. Round your answer to four decimal places. 
3. Question: A company wants to determine a confidence interval for the average CPU time of its teleprocessing transactions. A sample of 70 random transactions in milliseconds is … below. Assume that the transaction times follow a normal distribution with a standard deviation of 600 Use Excel to determine a 98% confidence interval for the average CPU time in milliseconds. Round your answers to the nearest integer and use ascending order.
4. Question: A sample of 22 test-tubes … for number of times they can … on a Bunsen burner before they crack is given below. Assume the counts are … Use Excel to construct a 99% confidence interval for μ. Round your answers to two decimal places and use increasing order.
5. Question: Suppose that the scores of bowlers in a particular league follow a normal distribution such that the standard deviation of the population is 12. Find the 95% confidence interval of the mean score for all bowlers in this league using the accompanying data set of 40 random scores. Round your answers to two decimal places and use ascending order.
6. Question: Suppose scores on exams in statistics are … with an unknown population mean. A sample of 26 scores is … Use Excel to find a 90% confidence interval for the true mean of statistics exam scores.
7. Question: In a random sample of 2,282 college students, 356 … getting 8 or more hours of sleep per night. Create a 95% confidence interval for the proportion of college students who get 8 or more hours of sleep per night.
8. Question: A restaurant is reviewing customer complaints. In a sample of 227 complaints, 57 complaints were about the slow speed of the service. Create a 95% confidence interval for the proportion of complaints that were about the slow speed of the service.
9. Question: The number of hours … per year per adult in a state is … with a standard deviation of 37. A sample of 115 adults is … at random, and the number of hours … per year per adult is … Use Excel to calculate the 98% confidence interval for the mean hours … per year for adults in this state
10. Question: Suppose the weights of tight ends in a football league are … such that σ2=1,369. A sample of 49 tight ends was … Use Excel to calculate the 95% confidence interval for the mean weight of all tight ends in this league.
11. Question: In a city, 22 coffee shops are randomly … , and the temperature of the coffee sold at each shop is noted. Use Excel to find the 90% confidence interval for the population mean temperature. Assume the temperatures are approximately normally distributed.
12. Question: An automobile shop manager … 27 employees and … the time, in minutes, it took them to change a water pump. Assuming normality, use Excel to find the 99% confidence interval for the true mean.
13. Question: A tax assessor wants to assess the mean property tax bill for all home owners in a certain state. From a survey ten years ago, a sample of 28 property tax bills is … Assume the property tax bills are approximately … Use Excel to construct a 95% confidence interval for the population mean property tax bill.
14. Question: A study was … to estimate the mean age when people buy their first new car. The ages of purchase for 22 randomly … Assume the ages are approximately … Use Excel to determine the 99% confidence interval for the mean.