A college has 220 ?full-time employees that are currently covered under the? school's health care plan. The average? out-of-pocket cost for the employees on the plan is ?$1,940 with a standard deviation of ?$520. The college is performing an audit of its health care plan and has randomly selected 30 employees to analyze their?out-of-pocket costs.
a. Calculate the standard error of the mean.
b. What is the probability that the sample mean will be less than ?$1,885??
c. What is the probability that the sample mean will be more than ?$1,905??
d. What is the probability that the sample mean will be between ?$1,965 and ?$1,990??
a. The standard error of the mean is