The average income in a state was $57,000 per person per year. Suppose the standard deviation is $21,000 and the distribution is right-skewed. Suppose we take a random sample of 100 residents of the state. Complete parts (a) and (b) below, a. What value should we expect for the sample mean? Why? The expected sample mean is $ 57000 , because the sample mean is an unbiased estimator of the population mean. (Type a whole number.) b. What is the standard error for the sample mean? The standard error for the sample mean is $ (Type an integer or a decimal, Do not round.)