In [1]:
x <- 1:16
n <- c(63526, 25653, 11855, 6055, 3264, 1727, 931, 497, 275, 124, 68, 28, 13, 6, 9, 4)
In [2]:
Q <- x[2:16] * n[2:16]/n[1:15]
plot(x[2:16], Q, type="p", pch=19, cex=1.5, xlim=c(0,16))
mod <- lm(Q[c(1:13, 15)] ~ x[c(2:14, 16)])
abline(mod, lty=2, lwd=2)