Considering the situation described, we have that:
At the null hypotheses, it is tested if the mean has not been reduced, that is, it still is of 5.2 hours, hence:
[tex]H_0: \mu = 5.2[/tex].
At the alternative hypothesis, it is tested if the mean has been reduced, that is, it is now of less than 5.2 hours, hence:
[tex]H_1: \mu < 5.2[/tex]
More can be learned about hypotheses tests at https://brainly.com/question/26454209