When the population standard deviation, i.e sigma is unknown, we use the formula involving t.
When the population standard deviation i.e sigma is known, we use the formula involving z.
When n<30, i.e sample size is not sufficiently large, t formula should be used to find out confidence interval, as population standard deviation is unknown.
answer the following questions Description Suppose you want to find the confidence interval for the mean....
Answer the following questions
Description Suppose you want to find the confidence interval for the mean. 1) When would you use the formula involving the t? 2) When would you use the formula involving the z? 3) If sigma is known, n < 30, and you have no information about the population distribution. Which of the following choices would be the correct course of action to take to find the confidence interval? (a) Use the t-formula (b) Use the z-formula...
supose you want to find the confidence interval for the mean. 1. when would you use the formula involving the t? 2. when would you use the formula involving the z? 3. if sigma is known, n <30, and you have no information about the population distribution. which of the following choices would be the correct course of action to take to find the confidence interval? a. use the t-formula b. use the z- formula c. something else
Which of the following is true about a 95% confidence interval, with a known sigma? a. The corresponding value for z is 1.65 b. 95% of similarly constructed intervals would contain the population mean. c. we can use either the t or z distribution, whichever we prefer d. All options are true
If we want to provide a 90% confidence interval for the mean of a population and the population standard deviation is known, the correct Z value is 0.95 1.96 0.485 1.645
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find tα/2,df for the following scenarios. (You may find it useful to reference the t table. Round your answers to 3 decimal places.) tα/2,df a. A 90% confidence level and a sample of 25 observations. b. A 95% confidence level and a sample of 25 observations.
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find tα/2,df for the following scenarios. (You may find it useful to reference the t table. Round your answers to 3 decimal places.) a. A 90% confidence level and a sample of 13 observations. b. A 95% confidence level and a sample of 13 observations. c. A 90%...
Use the standard normal distribution or the t-distribution to construct a 90% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 13 people, the mean length of stay at a hospital was 6.9 days. Assume the population standard deviation is 2.1 days and the lengths of stay are normally distributed. Which distribution should be used to construct the confidence interval? A. Use a normal...
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find ta/2, df for the following scenarios. (You may find It useful to reference the t table. Round your answers to 3 decimal places.) ta/2,df a. A 95 confidence level and a sample of 23 obeervations. b. A 99% confidence level and a sample of 23 observations. e....
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find tα/2,df for the following scenarios. (You may find it useful to reference the t table. Round your answers to 3 decimal places.) tα/2,df a. A 90% confidence level and a sample of 25 observations. b. A 95% confidence level and a sample of 25 observations. c. A...
We use the t distribution to construct a confidence interval for the population mean when the underlying population standard deviation is not known. Under the assumption that the population is normally distributed, find ta/2, df for the following scenarios. (You may find it useful to reference the t table. Round your answers to 3 decimal places.) ta/2,df a. b. 2.228 A 90% confidence level and a sample of 11 observations. A 95% confidence level and a sample of 11 observations....