The mean lung capacity for nonsmoking males in the population aged 50 is 2.2 liters. An investigator wants to examine if the mean lung capacities are significantly different among former smokers of similar backgrounds (i.e., males aged 50 who smoked in the past and are not currently smokers). A random sample of 28 former smokers is selected. Their lung capacities have a mean of 2.0 liters with a standard deviation of 0.41 liters. Calculate the appropriate test (by hand) at the 1% level of significance. Decide on a 1-tail or 2-tail test based on the goals of the research. Provide your answers in the spaces provided; do NOT show your work in the blanks.

The value for the calculated test statistic = The critical value =

Indicate your decision regarding the null hypothesis in the space provided using the following instructions: 1 for reject the null hypothesis; or write 2 to fail to reject the null hypothesis. Do NOT write any additional info as it will be marked as incorrect. My decision regarding the null hypothesis =