These are correct. And you should also know that the plural form is rarely used in spoken english. Most uneducated americans know what 'hypothesis' is, but not 'hypotheses'. It's a term you encounter in academic writing but rarely in speaking outside a classroom or laboratory. If you use this plural form in common speaking, outside a university, you will make uneducated people uncomfortable, as though you are using 'big words' on purpose to confuse them. Or else you will demonstrate that you are very intellectual but lacking in social skills. (or both!) Sorry to say this, but it's true. People learnign english do need to uinderstand that the academic form of written english you encounter in books is not the same as english as it is spoken and understood by people in the everyday world. As Strunk and White said, 'keep it simple'. Unless you are describing experiemental conditions, there's no reason not to use the much simpler and better understood word 'theories'.

That's right. Plural for hypothesis is "Hypotheses".

'Hypotheses' is the plural term for 'hypothesis.' "The experiment was designed to test the following four hypotheses . . ."