Question 636562
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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
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, 0,exp(-x^2/2)), blue(line( 1.5,0, 1.5,exp(-1.5^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}