{集中度:=(COST(85)-COST(15))/(COST(85)+COST(15))/2;}
pjcb:=((COST(45)+COST(55))/2+COST(35))/2,COLORyellow,LINETHICK2;
pjcb1:=((pjcb+ma(c,120))/2+(cost(50)+ma(c,120))/2)/2;
{pjcb1:=((cost(35)+ma(c,120))/2+cost(50))/2;}{也可用}
{pjcb:=((COST(50)+COST(50))/2+COST(35))/2,COLORyellow,LINETHICK2;}
pjcb2:=(cost(50)+pjcb1)/2;
pjcb3:=(pjcb1+pjcb2)/2;
平均成本:dma(pjcb3,1),coloryellow,linethick2;
ma(c,60);