Question 1140729
z=(x bar-mean)/sigma/sqrt(n)
so z1=-0.9/2/sqrt(4)=-0.9*2/2=-0.9 (invert the denominator and multiply, although it doesn't matter here)
z2=0.15*2/2=0.15
That probability, z between -0.9 and +0.15, is 0.3756