Final answer:
The hypothesis can be stated as follows: a. Manipulated variable: The amount of time students spend studying every night (20 minutes). b. Responding variable: Test scores achieved by students.
Step-by-step explanation:
The hypothesis regarding this issue can be stated as follows:
a. Manipulated variable: The amount of time students spend studying every night (20 minutes).
b. Responding variable: Test scores achieved by students.
To test this hypothesis, Mr. Coby can conduct an experiment where he divides the students into two groups. One group will study for 20 minutes every night, while the other group will not. At the end of a specified period, Mr. Coby can compare the test scores of both groups to determine if studying for 20 minutes every night leads to higher test scores.