a=[1 6/7 13/22 0 0 38/55 1 42/61 7/9 15/23 26/33 39/62 0 4/5 1 18/25];
cdfplot(a);
hold on
[f,x] = ecdf(a);
x1=[x(1:3)];y1=[f(1:3)];
plot(x1,y1,'r-')
hold on
x2=[x(3:13)],y2=[f(3:13)]
p=polyfit(x2,y2,5)
xi=0.59:0.01:1;
yi=polyval(p,xi)
plot(xi,yi,'r*')