A researcher is examining how long the work week of US physicians is. A random sample of 10,000 of US physicians indicates that the average work week if 58.44 hours/week. Assume that we know that the population standard deviation (? = 17.44).

A) How close is the sample meaning likely to be to the unknown population mean ?? Calculate standard error.

B) Determine the confidence interval on the assumption that the confidence level is 95%.