I conducted survey and the first variable in the questionnaire is about nightlife activities and it includes five questions. then the question is in likert item that is, the respondents will check if it is always sometimes or never. Then I want to know the relationship of hours they sleep at night and the nightlife activities. The hours is in interval scale. That is i code 1 for 9 -10 hours 2 for 11 - 12 hours and so on. What is the test applicable for this? please help! And if I want to know the impact of gender in the relationship, what test should I use? please help! i'm really confused.