An article reported that for a sample of 54 kitchens with gas cooking appliances monitored during a oneeweek period, the sample mean CO2 level (ppm) was 654.16, and the sample standard deviation was 162. (a) Calculate and interpret a 95% (twosided) condence 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.) (:.:)wm Interpret the resulting interval. 0 We are 95% condent that this interval does not contain the true population mean. 0 We are 95% condent that this interval contains the true population mean. 0 We are 95% condent that the true population mean lies above this interval. 0 We are 95% condent that the true population mean lies below this interval. (b) Suppose the investigators had made a rough guess of 174 for the value of 5 before collecting data. What sample size would be necessary to obtain an interval width of4l ppm for a confidence level of 95%? (Round your answer up to the nearest whole number.)