Step 1 :Let $p$ denote the population proportion of all Americans who prefer to watch the news rather than read or listen to it. We need to identify the null and alternative hypotheses.
Step 2 :The null hypothesis is the statement that is being tested. In this case, the null hypothesis is that half of Americans prefer to watch the news rather than read or listen to it.
Step 3 :The alternative hypothesis is the opposite of the null hypothesis. In this case, the alternative hypothesis is that fewer than half of Americans prefer to watch the news rather than read or listen to it.
Step 4 :So, we have: \[\begin{array}{ll} H_{0}: p = 0.5 \\ H_{1}: p < 0.5 \end{array}\]
Step 5 :Final Answer: \[\begin{array}{ll} H_{0}: p = \boxed{0.5} \\ H_{1}: p < \boxed{0.5} \end{array}\]