An Example
	q In an experiment, forty measurements of air temperature were made. The mean and standard deviation of the sample are:                               x = 18.41°C    and   s = 0.6283°C. Question 1:      Calculate the 95% confidence interval for the population mean for these data. Answer:      From the previous slid, we know the interval is: x ± Z95% * s / (N)0.5      Z95% = 1.96      Z95% * s / (N)0.5 = 1.96 * 0.6283°C / (40 )0.5 = 0.1947°C      The 95% confidence level for the population mean: 18.22°C ~ 18.60°C.