1. [0.7/2.81 Points] DETAILS PREVIOUS ANSWERS DEVORESTAT9 7.2.013. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER An article reported that for a sample of 43 kitchens with gas cooking appliances monitored during a one-week period, the sample mean CO, level (ppm) was 654.16, and the sample standard deviation was 162. (a) Calculate and interpret a 95% (two-sided) confidence interval for true average CO, level in the population of all homes from which the sample was selected. (Round your answers to two decimal places.) X .[ x ppm Interpret the resulting interval. We are 95% confident that this interval contains the true population mean. O We are 95% confident that the true population mean lies below this interval. We are 95% confident that this interval does not contain the true population mean. We are 95% confident that the true population mean lies above this interval. (b) Suppose the investigators had made a rough guess of 167 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 42 ppm for a confidence level of 95%? (Round your answer up to the nearest whole number.) kitchens You may need to use the appropriate table in the Appendix of Tables to answer this question. Need Help? Read It Submit Answer 2. [-/2.81 Points] DETAILS DEVORESTAT9 7.2.017. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A sample of ultimate tensile strength observations (ksi) was taken. Use the accompanying descriptive statistics output from Minitab to calculate a 99% lower confidence bound for true average ultimate tensile strength, and interpret the result. (Round your answer to two decimal places.) N Mear Median TrMean StDev SE Mean Minimum Maximum Q1 Q3 153 131 . 41 131 . 42 131 . 43 4. 47 0. 36 124 .20 149 . 80 133 . 65 138 . 45 We are 99% confident that the true average ultimate tensile strength is greater than ksi. You may need to use the appropriate table in the Appendix of Tables to answer this question. Need Help? Read It 3. [-/2.81 Points] DETAILS DEVORESTAT9 7.2.019. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER An article reported that, in a study of a particular wafer inspection process, 356 dies were examined by an inspection probe and 209 of these passed the probe. Assuming a stable process, calculate a 95% (two-sided) confidence interval for the proportion of all dies that pass the probe. (Round your answers to three decimal places.) You may need to use the appropriate table in the Appendix of Tables to answer this question. Need Help? Read It