An article reported that for a sample of 59 kitchens with gas cooking appliances monitored during a one-week period, the sample mean CO2 level (ppm) was 654.16, and the sample standard deviation was 165.4. (a) Calculate and interpret a 95% (two-sided) confidence interval for true average CO2 level in the population of all homes from which the sample was selected. (Round your answers to two decimal places.) ppm Interpret the resulting interval. We are 95% confident that the true population mean lies above this interval. 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 this interval contains the true population mean. (b) Suppose the investigators had made a rough guess of 183 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 59 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.