Chapter 8, Problem 9SE

Coin Flips (Example 2) A coin is flipped 30 times and comes up heads 18 times. You want to test the hypothesis that the coin does not come up $50\%$ heads in the long run.

Pick the correct null hypothesis for this test.

$\begin{array}{c}\text{ i}\text{. }{H}_0:\hat{p}=0.60\\ \text{ ii}\text{. }{H}_0:p=0.50\\ \text{ iii}\text{. }{H}_0:p=0.60\\ \text{ iv}\text{. }{H}_0:\hat{p}=0.50\end{array}$