I need help with these questions in my psychology class.

1. Stephen scored 145 on an IQ test with a mean of 100 and a standard deviation of 15. What is his z score?

2. For a language test with normally distributed scores, the mean was 70 and the standard deviation was 10. Approximately what percentages of test takers scored 60 and above?

3. Explain what a correlation coefficient is and how you would use it in research? If you looked at a study of students who study and pass the AP psychology exam and the correlation coefficient is +. 68, what would you conclude? How would your conclusion change is the correlation coefficient was +. 08? Explain.

4. Explain what statistical significance is and how you would use it in research? If you looked at an experiment if violent television causes violent behavior and had a statically significance p value of .05, what would you conclude about the research? Explain.

5. List two examples of a positive correlation between variables. List two examples of a negative correlation between variables.