please solve all parts ASAP

According to U.S. News & World Report's publication America's Best Colleges, the average cost to attend the University of Southern California (USC) after deducting grants based on need is $25,225. Assume the population standard deviation is $6,600. Suppose that a random sample of 40 USC students will be taken from this population. a. What is the value of the standard error of the mean? (to nearest whole number) b. What is the probability that the sample mean will be more than 25,225? (to 2 decimals) c. What is the probability that the sample mean will be within $750 of the population mean? (to 4 decimals) d. How would the probability in part (c) change if the sample size were increased to 190 (to 4 decimals)