9. Two different companies have applied to provide cable television service in a certain region. Let p denote the proportion of all potential subscribers who favor the first company over the second. Consider testing H0: p
.5 versus Ha: p .5 based on a random sample of 25 individuals. Let X denote the number in the sample who favor the first company and x represent the observed value of X.

a. Which of the following rejection regions is most appropriate and why?

R1
{x: x  7 or x  18}, R2
{x: x  8}, R3
{x: x  17}

b. In the context of this problem situation, describe what type I and type II errors are.