The following data represent the muzzle velocity (in feet per second) of rounds fired from a 155-mm gun. For each round, two measurements of the velocity were recorded using two different measuring devices, resulting in the following data. Complete parts (a) through (d) below. Observation 1 2 3 4 5 6 A 791.9 791.9 791.7 791.3 791.6 793.2 B 793.7 789.1 799.2 789.1 792.7 788.4