Physiologists often use the forced vital capacity as a way to assess a person's ability to move air in and out of their lungs. A researcher wishes to estimate the forced vital capacity of people suffering from asthma. A random sample of asthmatics yields the following data on forced vital capacity, in liters 3.7 3.7 4.3 3.5 5.2 (a) Use the data to obtain a 95% confidence interval for the mean forced vital capacity for all asthmatics if the standard deviation of forced vital capacity for all people suffering from asthma is 0.8. Be sure to interpret your answer.
(b) This confidence interval was a z/t interval because the population standard devia- tion is known/unknown. (Circle the correct choice for each.)