Ahuman factors psychologist wants to know if a new computer-generated voice is either easier or harder to comprehend than human speech. to test this, he gathers 30 volunteers and assigns each to one of two groups. both groups hear a selection being read. one group's selection is read in the computer-generated voice, the other is read by a human. the results of the experiment, the number of words from the selection that were transcribed correctly, are presented below. is there a difference in comprehensibility