Considering the situation described, we have that:
- The appropriate null hypotheses is
.
- The appropriate alternative hypotheses is
.
<h3>What are the hypotheses tested?</h3>
At the null hypotheses, it is tested if the mean has not been reduced, that is, it still is of 5.2 hours, hence:
.
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:

More can be learned about hypotheses tests at brainly.com/question/26454209
I assume c, because usually to get to the opposite you reflect the line or figure on the x axis
This is referred to as a Chemical Bond.
Answer:
x=-27
Step-by-step explanation:
x/-9=3
x=3*-9=-27