SOLUTION: If the random variable z is the standard normal score and a > 0, is it true that P(0 < z < a) = 1 - P(z < a)? Why or why not?

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Question 636562: If the random variable z is the standard normal score and a > 0, is it true that P(0 < z < a) = 1 - P(z < a)? Why or why not?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

Important to Understand z -values as they relate to the Standard Normal curve:

Note: z = 0 (x value, the mean) 50% of the area under the curve is to the left and 50%  to the right



P(0 < z < a) =  P(z < a) - .5  when a > 0.   Below example,  z = 1.5

P(z < 1.5) represents the % of the area under the curve that is to the left of z = 1.5