Please explain how you are determining when you make the z-score negative and when to make the z-score positive in the following answers:

7. The z-score for the cumulative 20% of the data distribution.

0.20

0.5-0.20

0.3

z-score=

-0.85

8. The z-score for the upper 20% of the data distribution.

0.20

0.5-0.20

0.3

z-score=

-0.85

9. The z-score that corresponds to a cumulative value of .3974

0.5-0.3974

0.1026

z-score=

-0.26

10. The z-score that represents the cumulative value of .2984

0.5-0.2984

0.2016

0.53