Check the hypothesis of problems 10 and 11 with Wessa.net.10. Test the hypothesis that the average monthly income per family is $2,500. After conducting a survey with 50 families, it was found that the average of the sample was $2,125 with a population standard deviation of $135. A 99% level of confidence in the test is desired. 11. You want to test the hypothesis that the average demand for a product is 900 units per week. After surveying 58 clients, it was found that the sample average was 810 units with a standard deviation of 90.