Construct 90%, 95%, and 99% confidence intervals forthe population mean, and state the practical and probabilisticinterpretations of each. Indicate which interpretation you thinkwould be more appropriate to use. Explain why the three intervalsthat you construct are not of equal width. Indicate which of thethree intervals you would prefer to use as an estimate of thepopulation mean, and state the reason for your choice.
In a length of hospitalization study conducted by severalcooperating hospitals, a random sample of 64 peptic ulcer patientswas drawn from a list of all peptic ulcer patients ever admitted tothe participating hospitals and the length of hospitalization peradmission was determined for each. The mean length ofhospitalization was found to be 8.25 days. The population standarddeviation is known to be 3 days.
For each confidence interval indicate
a) Z-critical values ,
b) Error,
c) confidence interval
