Answer:
a)
b)
Step-by-step explanation:
The National Institute of Mental Health published an article stating that in any one-year period, approximately 9.5 percent of American adults suffer from depression or a depressive illness.
At the null hypothesis, we test if the value we find is equal to the expected value, that is:
Test to determine if the true proportion of people in that town suffering from depression or a depressive illness is lower than the percent in the general adult American population
Lower, which means that the alternate hypothesis, we test if the value we find is lower than the expected value, that is: