Hi,

This is not a homework question as I have the answer, just trying to figure out the method;

I have a "Normal Distribution Table" infront of me.

Sample mean = 76.8
Standard Deviation = 12.43
n = 40, m = 8 intervals

And below are the defined intervals of the standard normal variable (z).
What I do not understand is how the values 1.15, 0.675, 0.32, 0.00 have been produced. Could someone kindly inform me / show me,


Prob (z < -1.15) = 0.125
Prob (-1.15 < -0.675) = 0.125
Prob (-0.675 < -0.32) = 0.125
Prob (-0.32 < -0.00) = 0.125
Prob ( 0.00 < +0.32) = 0.125
Prob ( 0.32 < +0.675) = 0.125
Prob ( 0.675 < +1.15) = 0.125
Prob ( z > +1.15) = 0.125

Thanks