## MATH 225N Week 6 Assignment Confidence Interval for Mean – Population Standard Deviation Known

#### MATH 225N Week 6 Assignment Confidence Interval for Mean – Population Standard Deviation Known (A)

**Question:**The population standard deviation for the number of corn kernels on an ear of corn is 94 If we want to … 90%confident that the sample mean is within 17kernels of the true population mean, what is the minimum sample size that should … taken?**Question:**Suppose the scores of a standardized test are … If the population standard deviation is2 points, what minimum sample size is … 90% confident that the sample mean is within 1 point of the true population mean?**Question:**The length, in words, of the essays written for a contest are … with a population standard deviation of 442words and an unknown population mean. If a random sample of 24 essays is … and results in a sample mean of 1330 words, find a 99% confidence interval for the population mean.**Question:**The lengths, in inches, of adult corn snakes are … with a population standard deviation of 8inches and an unknown population mean. A random sample of 25 snakes is … and results in a sample mean of 58 Identify the parameters … calculate a confidence interval at the 99% confidence level. Then find the confidence interval.**Question:**The lengths, in inches, of adult corn snakes are … with a population standard deviation of8 inches and an unknown population mean. A random sample of 25 snakes is … and results in a sample mean of 58 What is the correct interpretation of the confidence interval?**Question:**The weights, in pounds, of dogs in a city are … with a population standard deviation of 2pounds and an unknown population mean. A random sample of 16 dogs is … and results in a sample mean of 28 Identify the parameters … calculate a confidence interval at the 90% confidence level. Then find the confidence interval….. You may use a calculator or the common z values above. Round the final answer to two decimal places.**Question:**The weights, in pounds, of dogs in a city are … with a population standard deviation of2 pounds and an unknown population mean. A random sample of 16 dogs is … and results in a sample mean of 28 pounds….. What is the correct interpretation of the confidence interval?**Question:**Suppose heights of dogs, in inches, in a city are … and have a known population standard deviation of 7inches and an unknown population mean. A random sample of 15dogs is … and gives a sample mean of 34 Find the confidence interval for the population mean with a 99% confidence level….. z0.10 z0.05 z0.025 z0.01 z0.005… 1.282 1.645 1.960 2.326 2.576…. You may use a calculator or the common z values above. Round the final answer to two decimal places.**Question:**The germination periods, in days, for grass seed are … with a population standard deviation of5 days and an unknown population mean. If a random sample of 17 types of grass seed is … and results in a sample mean of 52days, find a 80% confidence interval for the population mean.**Question:**Suppose scores of a standardized test are … and have a known population standard deviation of 6points and an unknown population mean. A random sample of 22 scores is … and gives a sample mean of 92 Identify the parameters … calculate a confidence interval at the 98% confidence level. Then find the confidence interval….. You may use a calculator or the common z values above.**Question:**Suppose scores of a standardized test are … and have a known population standard deviation of6 points and an unknown population mean. A random sample of 22 scores is … and gives a sample mean of 92 points….. What is the correct interpretation of the 98% confidence interval?**Question:**Suppose the heights of seasonal pine saplings are … If the population standard deviation is 14millimeters, what minimum sample size is … 95%confident that the sample mean is within 4 millimeters of the true population mean?…**10**1.282**z0.05**1.645**z0.025**1.960**z0.01**2.326**z0.005**2.576 ….. Use the table above for the z-score, and … sure to round up to the nearest integer.**Question:**The population standard deviation for the scores of a standardized test is4 If we want to … 90% confident that the sample mean is within 1 point of the true population mean, what is the minimum sample size that should … ?….**z****0.10**1.282**z****0.05**1.645**z****0.025**1.960**z****0.01**2.326**z****0.005**2.576….. Use the table above for the z-score, and … sure to round up to the nearest integer.

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#### MATH 225N Week 6 Assignment Confidence Interval for Mean – Population Standard Deviation Known (B)

**Question:**Suppose the germination periods, in days, for grass seed are … If the population standard deviation is 3 days, what minimum sample size is … 90% confident that the sample mean is within 1 day of the true population mean?**Question:**The length, in words, of the essays written for a contest are … with a population standard deviation of 442 words and an unknown population mean. If a random sample of 24 essays is … and results in a sample mean of 1330 words, find a 99% confidence interval for the population mean.**Question:**The lengths, in inches, of adult corn snakes are … with a population standard deviation of 8 inches and an unknown population mean. A random sample of 25 snakes is … and results in a sample mean of 58….. Identify the parameters … calculate a confidence interval at the 99% confidence level. Then find the confidence interval.**Question:**The lengths, in inches, of adult corn snakes are .. with a population standard deviation of 8 inches and an unknown population mean. A random sample of 25 snakes is … and results in a sample mean of 58…. What is the correct interpretation of the confidence interval?**Question:**Suppose the scores of a standardized test are … If the population standard deviation is 2 points, what minimum sample size is … 90% confident that the sample mean is within 1 point of the true population mean?**Question:**The weights, in pounds, of dogs in a city are … with a population standard deviation of 2 pounds and an unknown population mean. A random sample of 16 dogs is … and results in a sample mean of 28…. Identify the parameters … calculate a confidence interval at the 90% confidence level. Then find the confidence interval.**Question:**The weights, in pounds, of dogs in a city are … with a population standard deviation of 2 pounds and an unknown population mean. A random sample of 16 dogs is … and results in a sample mean of 28…. What is the correct interpretation of the confidence interval?**Question:**Suppose heights of dogs, in inches, in a city are … and have a known population standard deviation of 7 inches and an unknown population mean. A random sample of 15 dogs is … and gives a sample mean of 34 Find the confidence interval for the population mean with a 99% confidence level.**Question:**The germination periods, in days, for grass seed are … with a population standard deviation of 5 days and an unknown population mean. If a random sample of 17 types of grass seed is … and results in a sample mean of 52 days, find a 80% confidence interval for the population mean.**Question:**Suppose scores of a standardized test are … and have a known population standard deviation of 6 points and an unknown population mean. A random sample of 22 scores is … and gives a sample mean of 92….. Identify the parameters … calculate a confidence interval at the 98% confidence level. Then find the confidence interval.**Question:**Suppose scores of a standardized test are … and have a known population standard deviation of 6points and an unknown population mean. A random sample of 22 scores is … and gives a sample mean of 92….. What is the correct interpretation of the 95% confidence interval?**Question:**Suppose the heights of seasonal pine saplings are … If the population standard deviation is 14 millimeters, what minimum sample size is … 95% confident that the sample mean is within 4 millimeters of the true population mean?**Question:**The population standard deviation for the scores of a standardized test is 4 If we want to … 90% confident that the sample mean is within 1 point of the true population mean, what is the minimum sample size that should … ?**Question:**The population standard deviation for the total snowfalls per year in a city is 13 If we want to … 95% confident that the sample mean is within 3 inches of the true population mean, what is the minimum sample size that should … ?**Question:**The population standard deviation for the lengths, in seconds, of the songs in an online database is 15 If we want to … 90% confident that the sample mean is within 4seconds of the true population mean, what is the minimum sample size that should … ?**Question:**The population standard deviation for the number of corn kernels on an ear of corn is 94 If we want to … 90% confident that the sample mean is within 17 kernels of the true population mean, what is the minimum sample size that should … ?**Question:**Suppose the weights, in pounds, of the dogs in a city are … If the population standard deviation is 3 pounds, what minimum sample size is … 95% confident that the sample mean is within 1 pound of the true population mean?**Question:**Suppose the number of dollars spent per week on groceries is … If the population standard deviation is 7 dollars, what minimum sample size is … 90% confident that the sample mean is within 3 dollars of the true population mean?**Question:**Suppose the speeds of vehicles traveling on a highway are … If the population standard deviation is 2 miles per hour, what minimum sample size is … 90% confident that the sample mean is within 1 mile per hour of the true population mean?**Question:**A College Board sample estimated the standard deviation of 2016 SAT scores to … 194 You are researching the average SAT score. You want to know how many people you should survey if you want to know, at a 98% confidence level, that the sample mean SAT score is within 50 points of the true mean SAT score. What value for*z*should you use in the sample size formula?**Question:**You are researching the average SAT score, and you want to know how many people you should survey if you want to know, at a 98% confidence level, that the sample mean score is within 50 points of the true population mean. From above, we know that the population standard deviation is 194, and*z*01=2.326. What is the minimum sample size that should … surveyed?**Question:**A television network wants to estimate the average number of hours of TV watched each week by viewers. The network decides to create a 95% confidence interval for the average number of hours of TV watched each week. How large of a sample size of viewers should … to create this confidence interval if the television network wants to be 95% confident that the sample mean is within 1 hour of the population mean? Assume the standard deviation for the number of hours of TV watched each week is 5. 97 viewers**Question:**Suppose the number of square feet per house is … If the population standard deviation is 155 square feet, what minimum sample size is … 90% confident that the sample mean is within 47 square feet of the true population mean?**Question:**The population standard deviation for the typing speeds for secretaries is 4 words per minute. If we want to … 90% confident that the sample mean is within 1 word per minute of the true population mean, what is the minimum sample size that should … ?**Question:**The population standard deviation for the body weights of the employees of a company is 10 If we want to … 95% confident that the sample mean is within 3 pounds of the true population mean, what is the minimum sample size that should … ?**Question:**The population standard deviation for the scores of a standardized test is 5 If we want to … 95% confident that the sample mean is within 2 points of the true population mean, what is the minimum sample size that should … ?**Question:**Suppose the scores of a standardized test are … If the population standard deviation is 4 points, what minimum sample size is … 95% confident that the sample mean is within 1 point of the true population mean?**Question:**The population standard deviation for the lengths, in words, of the essays written for a contest is 542 If we want to … 90% confident that the sample mean is within 141 words of the true population mean, what is the minimum sample size that should … ?**Question:**Suppose the total snowfalls per year in a city are … If the population standard deviation is 13 inches, what minimum sample size is … 95% confident that the sample mean is within 4 inches of the true population mean?**Question:**Suppose the finishing times for cyclists in a race are … If the population standard deviation is 16 minutes, what minimum sample size is … 90% confident that the sample mean is within 5 minutes of the true population mean?**Question:**The population standard deviation for the number of pills in a supplement bottle is 16 If we want to … 95% confident that the sample mean is within 5 pills of the true population mean, what is the minimum sample size that should … ?