here is the question please explain why you chose the answer

For the following scenario, determine whether the alternative hypothesis would be one-sided or two-sided. According to enrollment data in 2016, 55% of undergraduates at a state university were out-of-state students. Your statistics instructor wonders if the proportion of out-of-state undergraduates at this university has changed. She surveys her students (145 students). The results of the sample showed that 73 were out-of-state students. 0 one-sided O two-sided