Question: The population standard deviation for the number of corn kernels on an ear of corn is 94 kernels. If we want to be 90%confident that the sample mean is within 17 kernels of the true population mean, what is the minimum sample size that should be taken?
Question: Suppose the scores of a standardized test are normally distributed. If the population standard deviation is 2 points, what minimum sample size is needed to be 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 normally distributed with a population standard deviation of 442 words and an unknown population mean. If a random sample of 24 essays is taken 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 normally distributed with a population standard deviation of 8 inches and an unknown population mean. A random sample of 25 snakes is taken and results in a sample mean of 58 inches. Identify the parameters needed to calculate a confidence interval at the 99% confidence level. Then find the confidence interval.
Question: The lengths, in inches, of adult corn snakes are normally distributed with a population standard deviation of 8 inches and an unknown population mean. A random sample of 25 snakes is taken and results in a sample mean of 58 inches. What is the correct interpretation of the confidence interval?
Question: The weights, in pounds, of dogs in a city are normally distributed with a population standard deviation of 2 pounds and an unknown population mean. A random sample of 16 dogs is taken and results in a sample mean of 28 pounds. Identify the parameters needed to 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 normally distributed with a population standard deviation of 2 pounds and an unknown population mean. A random sample of 16 dogs is taken 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 normally distributed and have a known population standard deviation of 7inches and an unknown population mean. A random sample of 15 dogs is taken and gives a sample mean of 34 inches. 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 normally distributed with a population standard deviation of 5 days and an unknown population mean. If a random sample of 17 types of grass seed is taken 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 normally distributed and have a known population standard deviation of 6 points and an unknown population mean. A random sample of 22 scores is taken and gives a sample mean of 92 points. Identify the parameters needed to 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 normally distributed and have a known population standard deviation of 6 points and an unknown population mean. A random sample of 22 scores is taken 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 normally distributed. If the population standard deviation is 14millimeters, what minimum sample size is needed to be 95% confident that the sample mean is within 4 millimeters of the true population mean? …. z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576….. Use the table above for the z-score, and be sure to round up to the nearest integer.
Question: The population standard deviation for the scores of a standardized test is 4 points. If we want to be 90% confident that the sample mean is within 1 point of the true population mean, what is the minimum sample size that should be taken?.... z0.101.282z0.051.645z0.0251.960z0.012.326z0.0052.576….. Use the table above for the z-score, and be sure to round up to the nearest integer.
Instituition / Term
Term
Summer 2020
Institution
MATH 225N Statistical Reasoning for the Health Sciences
