http://t3x.org/klong-stat/f07.kg.html (light|dark)
.l("config.kg")
grid([-3 3 1];[0 1 0.1])
Plot t-distribution PDF with nu=3
plot(t.pdf(3;))
Compute t-score for 0.95'th quantile and fill the corresponding confidence interval
t::t.qf(3;0.95) area(-t;t;0)
Re-draw the grid over the filled area
grid([-3 3 1];[0 1 0.1])
Draw vertical bars on the left and right borders of the area
vline(-2.35) vline(2.35) draw()