4.17 A random sample of size 13 is drawn from an unknown continuous population FX(x), with the following results after array:

3.5, 4.1, 4.8, 5.0, 6.3, 7.1, 7.2, 7.8, 8.1, 8.4, 8.6, 9.0 A 90% confidence band is desired for FX(x). Plot a graph of the empirical distribution function Sn(x) and resulting confidence bands.