3.13 Table A. Use Table A to find the value z of a standard Normal variable that satisfies each of the following conditions. (Use the value of z from Table A that comes closest to satisfying the condition.) In each case, sketch a standard Normal curve with your value of z marked on the axis.

(a) The point z with 75% of the observations falling below it

(b) The point z with 15% of the observations falling above it

(c) The point z with 15% of the observations falling below it