Need help understanding questions 8-16 about finding z scores from percentiles.

8. Mean = 3 0 = .8 find the z-score associated with an area of .99 9. Mean = 65 a = 15 find the z-scores centered about the mean containing 96 percent of the data 10. Mean = 4 o = .6 find the z-score associated with a probability of .2 11. Mean = 7 o = -.32 find the z-score associated with an area of .80 12. Mean = 4 o = .2 find the z-score associated with the upper 45% of the data 20: 2 -17 79 13. Mean = 10 = .8 What Z-scores are associated with a lower and upper quartile ranking? 14. Mean = 103 = 12 What Z-score is associated with the upper 10% of the data? 15. What Z-scores centered about the mean contain 54% of the data? 16. What Z-scores centered about the mean contain 80% of the data