x=(-250:350)/100
y=ifelse(x>3,1,ifelse(x>2,.85,
	ifelse(x>1,.8,ifelse(x>0,.5,
		ifelse(x>-1,.35,ifelse(x>-2,.3,.15))))))
plot(x,y,type="l",xlab="x",ylab="P(X<=x)")