Question 1179009
{{{drawing(400,200,-5,5,-.5,1.5, graph(400,200,-5,5,-.5,1.5, exp(-x^2/2)), green(line(1,0,1,exp(-1^2/2)),line(-1,0,-1,exp(-1^2/2))),green(line(2,0,2,exp(-2^2/2)),line(-2,0,-2,exp(-2^2/2))),green(line(3,0,3,exp(-3^2/2)),line(-3,0,-3,exp(-3^2/2))),green(line( 0,0, 0,exp(0^2/2))),locate(4.8,-.01,z),locate(4.8,.2,z))}}}
middle 32%:  16% on either side of Mean(which is 50% from left & right)
 66% - 34% is the middle 32%
Using TI or similarly an inexpensive calculator like an Casio fx-115 ES plus
z1 = invNorm(.66) = .4125
z2 = invNorm(.34) = -.4125