10, do manually

8. What does a z-score measure? 9. What does standardizing a normal distribution do to the mean? 10. Is X ~ N(0, 1) a standardized normal distribution? Why or why not? 11. What is the z-score of x = 12, if it is two standard deviations to the right of the mean? 12. What is the z-score of x = 9, if it is 1.5 standard deviations to the left of the mean? 13. What is the z-score of x = -2, if it is 2.78 standard deviations to the right of the mean