The social service department of a local government agency is interested in estimating the median annual income of families living in the district. They took a sample of 50 families and found that their average annual income was $ 11,850.00 with a standard deviation of $ 950.00. Calculate:

a) Calculate the average annual income of the district in a timely manner

Solution:

b) Calculate the average annual income for the district, with a 95% confidence interval

Solution:

c) Calculate the average annual income of the district, with a confidence interval of 90%

Solution: