An article reported that for a sample of 44 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 162.68. a) Calculate and interpret a 95% two sided confidence interval for true average CO2 level n the population of a homes from hich the sample as selected.
Interpret the resulting interval.
a. we are 95% confident that the true population mean lies above this interval.
b. we are 95% confident that this interval does not contain the true population mean.
c. we are 95% confident that the true population mean lies below this interval.
d. we are 95% confident that this interval contains the true population mean.
(b) Suppose the investigators had made a rough guess of 181 for the value of s before collecting data. What sample size would be necessary to obtain an interval width of 60 ppm for a confidence level of 95%?