Ranking PhD programs in economics. Refer to the Southern Economic Journal rankings of PhD programs in economics at 129 colleges and universities, Exercise 2.105 (p. 111). Recall that the number of publications published by faculty teaching in the PhD program and the quality of the publications were used to calculate an overall productivity score for each program. The mean and standard deviation of these 129 productivity scores were then used to compute a z-score for each economics program. The data (z-scores) for all 129 economic programs are saved in the accompanying file. A Minitab normal probability plot for the z-scores is shown below. Use the graph to assess whether the data are approximately normal. ECOPHD