Question c. is an either an increase or a decrease
Question c. is an either an increase or a decrease 18. 6.66 points A sample of...
A sample of 23 observations is selected from a normal population where the population standard deviation is 28. The sample mean is 71. a. Determine the standard error of the mean. (Round the final answer to 3 decimal places.) The standard error of the mean is . b. Determine the 95% confidence interval for the population mean. (Round the z-value to 2 decimal places. Round the final answers to 3 decimal places.) The 95% confidence interval for the population mean is...
A sample of 24 observations is selected from a normal population where the sample standard deviation is 4.45. The sample mean is 16.45. a. Determine the standard error of the mean. (Round the final answer to 2 decimal places.) The standard error of the mean is. b. Determine the 90% confidence interval for the population mean. (Round the t-value to 3 decimal places. Round the final answers to 3 decimal places.) The 90% confidence interval for the population mean is...
A random sample of 24 observations is used to estimate the population mean. The sample mean and the sample standard deviation are calculated as 128.4 and 26.80, respectively. Assume that the population is normally distributed. [You may find it useful to reference the t table.) a. Construct the 95% confidence interval for the population mean. (Round intermediate calculations to at least 4 decimal places. Round "t" value to 3 decimal places and final answers to 2 decimal places.) Confidence interval...
Let the following sample of 8 observations be drawn from a normal population with unknown mean and standard deviation: 24, 22, 14, 26, 28, 16, 20, 21. [You may find it useful to reference the t table.) a. Calculate the sample mean and the sample standard deviation (Round intermediate calculations to at least 4 decimal places. Round "Sample mean" to 3 decimal places and "Sample standard deviation" to 2 decimal places.) Answer is complete but not entirely correct. Sample mean...
A sample of 240 observations is selected from a normal population with a population standard deviation of 24. The sample mean is 20. Determine the standard error of the mean. (Round your answer to 3 decimal places.) Determine the 90% confidence interval for the population mean. (Use z Distribution Table.) (Round your answers to 3 decimal places.)
A simple random sample of 24 observations is derived from a normally distributed population with a known standard deviation of 7.8. [You may find it useful to reference the z table.] a. Is the condition that X−X− is normally distributed satisfied? Yes No b. Compute the margin of error with 99% confidence. (Round intermediate calculations to at least 4 decimal places. Round "z" value to 3 decimal places and final answer to 2 decimal places.) Margin error: ? c. Compute...
AM You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals. A random sample of 35 home theater systems has a mean price of $144.00. Assume the population standard deviation is $15.60. Construct a 90% confidence interval for the population mean. The 90% confidence...
The average American young adult spends $140 on smartphone expenses per month, with a known population standard deviation of 28.2. In order to compute a confidence interval estimate for the population mean, a sample of 66 observations is drawn. Use Table 1. a. Is the condition that X−X− is normally distributed satisfied? Yes No b. Compute the margin of error at a 95% confidence level. (Round intermediate calculations to 4 decimal places. Round final answer to 2 decimal places.) Margin of...
ind tα,df from the following information. [You may find it useful to reference the t table.] tα,df a. α = 0.005 and df = 18 b. α = 0.20 and df = 18 c. α = 0.005 and df = 22 d. α = 0.20 and df = 22 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...
to estimate the population mean repair cost of microwave ovens in macomb, a random sample of 9 broken microwave ovens was selected and it is found that the sample mean repair cost was $80 with a sample standard deviation of $15. 1) what would be the “critical value” if you want to find a 95% confidence interval for the population mean? 2) what would be the “margin of error” if you want to find a 95% confidence interval for the...