pls help with hw question

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 LO CO 793.5 790.5 793.5 791.4 792.3 793.9 m 801.8 789.0 803.4 788.7 795.4 789.0 (a) why are these matched-pairs data? A. The same round was fired in every trial. O B. The measurements (A and B) are taken by the same instrument. C. Two measurements (A and B) are taken on the same round. O D. All the measurements came from rounds fired from the same gun. (b) Is there a difference in the measurement of the muzzle velocity between device A and device B at the a = 0.01 level of significance? Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers. Let d, = A - B. Identify the null and alternative hypotheses. Ho: Hd Hy : Hd H