Question 364629
Between {{{-infinity}}} and {{{z=0}}}, 50% of the distribution lies.
Between {{{-infinity}}} and {{{z=z[1]}}}, X% of the distribution lies. 
So then between {{{z[1]}}} and {{{z=0}}}, 30.78% of the distribution lies.
{{{X=50-30.78=19.22}}}
Find {{{z[1]}}}, so that {{{P(z[1])=0.1922}}}
Using EXCEL's NORMSINV function,
{{{highlight(z[1]=-0.86982)}}}