Question: Two different companies (A and B) have applied to provide cable television service in a certain region. Let p denote the proportion of all potential subscribers who favor the company A over the company B based on a random sample of 25 individuals. Consider the case that company A wants to increase its production. Let the test statistic X be the number in the sample who favor the first company and x represent the observed value of X. What are the appropriate null and alternative hypotheses?
The answer is $H_0:p=0.5$, $H_a:p>0.5$
Where is $0.5$ coming from?