if income in the US was normally distributed, what z-score would represent the bottom 10%, the poorest 10%

Answer 1

I have a table of z versus F(z)
it shows for F(z) = .1 or 10 %, z = -1.3 or 1.3 standard deviations below mean

Answer 2

I studied Spanish from a book entitled "El Camino Real" when I was in the 8th grade more than 65 years ago. I wonder how anyone would guess from this post title that the problem was one in statistics?