Answer:
1.282, -0.5244,...
Step-by-step explanation:
We know that Z is a standard normal variate with mean =0, and std dev =1
a) z-score separates the highest 10% from the rest of the scores
= 90th percentile = 1.282
b) z-score separates the lowest 30% from the rest of the scores
= 30th percentile = -0.5244
c) z-score separates the lowest 40% from the rest of the scores
= 40th percentile = -0.2533
d) z-score separates the lowest 20% from the rest of the score
=20th percentile = -0.8416
