The Table Below Shows the Mean Number of Daily Errors

Multiple Choice

The table below shows the mean number of daily errors by air traffic controller trainees during the first two weeks on the job.We want to perform a paired t-test at  = .05 to see if the mean daily errors decreased significantly. The test statistic is:

A) 1.25
B) 1.75
C) 0.87
D) 0.79