The mean rent for a one-bedroom apartment in a certain city is $1,200 per month. The distribution of the monthly costs does not follow the normal distribution. In fact, it is positively skewed. The standard deviation of the population is $250.
a. What is the probability of selecting a sample of 50 one-bedroom apartments and finding the mean to be at least $1150 per month?
b. Compute the standard error of the mean if the sample size was 20.