swim <-
structure(list(swimmer.number = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 
10, 11, 12), wet.suit.velocity = c(1.5700000000000001, 1.47, 
1.4199999999999999, 1.3500000000000001, 1.22, 1.75, 1.6399999999999999, 
1.5700000000000001, 1.5600000000000001, 1.53, 1.49, 1.51), swim.suit.velocity = c(1.49, 
1.3700000000000001, 1.3500000000000001, 1.27, 1.1200000000000001, 
1.6399999999999999, 1.5900000000000001, 1.52, 1.5, 1.45, 1.4399999999999999, 
1.4099999999999999), velocity.diff = c(0.080000000000000071, 
0.099999999999999867, 0.06999999999999984, 0.080000000000000071, 
0.099999999999999867, 0.1100000000000001, 0.049999999999999822, 
0.050000000000000044, 0.060000000000000053, 0.080000000000000071, 
0.050000000000000044, 0.10000000000000009)), row.names = c(NA, 
-12L), class = "data.frame")