An independent random sample of 396 cases from Insurer B gave the results for length of stay summarized in Display 9.38.
a. Is it appropriate to construct a confidence interval without transforming these data? Explain.
b. Regardless of your answer to part a, estimate the mean LOS for Insurer B in a 90% confidence interval.
c. Would you be more concerned about constructing a confidence interval without a transformation if the sample size was 40 instead of nearly 400? What about a sample size of 4 instead of nearly 400?
d. Compare your confidence intervals in part b of E43 and E44. Does it appear that the two insurers differ in mean LOS?