Section 6.1

Section 6.1 Find the critical value ze necessary to form a confidence interval at the level of confidence shown below. C= 0.81 1. ) (Round to two decimal places as needed.) Find the critical value ze necessary to form a confidence interval at the level of confidence shown below. C = 0.92 Ze = (Round to two decimal places as needed.) 2.) 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 From a random sample of 32 business days, the mean closing price of a certain stock was $113.73. Assume the population standard deviation is $11.03. The 90% confidence interval is ( 110 52 , 116.94). (Round to two decimal places as needed.) The 95% confidence interval is ( 109 91 . 117.55) 3.) (Round to two decimal places as needed.)Determine the minimum sample size required when you want to be 95% confident that the sample mean is within one unit of the population mean and o = 14.4. Assume the population is normally distributed. A 95% confidence level requires a sample size of (Round up to the nearest whole number as needed.) 4.) A cheese processing company wants to estimate the mean cholesterol content of all one-ounce servings of a type of cheese. The estimate must be within 0.69 milligram of the population mean. (a) Determine the minimum sample size required to construct a 95% confidence interval for the population mean. Assume the population standard deviation is 3.08 milligrams. (b) The sample mean is 25 milligrams. Using the minimum sample size with a 95% level of confidence, does it seem likely that the population mean could be within 3% of the sample mean? within 0.3% of the sample mean? Explain. Click here to view page 1 of the Standard Normal Table. Click here view page 2 of the Standard Normal Table 5.)