Health Insurers and the Federal Government Are Both Putting Pressure

Multiple Choice

Health insurers and the federal government are both putting pressure on hospitals to shorten the average length of stay (LOS) of their patients.In 1996,the average LOS for non-heart patient was 4.6 days.A random sample of 20 hospitals had a mean LOS for non-heart patients in 2000 of 3.8 days and a standard deviation of 1.2 days.Assume LOS is normally distributed.How large a sample of hospitals would we need to be 99% confident that the sample mean is within 0.5 days of the population mean?

A) 3
B) 7
C) 32
D) 48
E) 96