'15:32 30/01/2026
'CP

'area under normal distribution curve
'integral

int i
double pf=1/sqr(2*pi())
'pf=1
double x1=0.0, x2=0.0
double pa=0.0
double h=0.5
'between 2 and 3 standard deviations
int bg=20000
int en=30000
x1=bg/10000
for i=bg to en
  x2=x1+0.0001
  pa+=exp(-h*x1*x2) 'integral
  x1=x2
next
print str(pa*pf,2)" /10000"
