Consider the following four (x, y) data sets; the first three have the same x values, so these values are listed only once

(Frank Anscombe, “Graphs in Statistical Analysis,”Amer.

Statistician, 1973: 17–21)

has a standard normal distribution. If is substituted for s, the resulting variable has a t distribution with df. By analogy, what is the distribution of any particular standardized residual? If , what is the probability that a particular standardized residual falls outside the interval (2.50, 2.50)?