For each of the following, state the null (H0) and alternative (H1) hypotheses.

·     Has the mean community level of suspended particulates for the month of August exceeded 30 units per cubic meter?

·     Is the average cross-sectional area of the lumen of coronary arteries for men ages 40-59 less than 31.5% of the toal arterial cross section?

·     Is the mean hemoglobin level of a group of high-altitude workers different from 16 g/cc?

·     Does the mean speed of 50 cars as checked by radar on a particular highway differ from 65 mph?