Question

Ranking PhD programs in economics. Refer to the SouthernEconomic Journal(April 2008) rankings of PhD programsin economics at 129 colleges and universities, Exercise 2.103(p. 117). Recall that the number of publications published byfaculty teaching in the PhD program and the quality of thepublications were used to calculate an overall productivityscore for each program. The mean and standard deviationof these 129 productivity scores were then used to computea 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 isshown below. Use the graph to assess whether the data areapproximately normal.

Short answer

The quantile- quantile line and data points are not falling approximately one upon another. So, the data score is not normally distributed.

Step-by-step solution

Given information

The graph of the 129 productivity scores is given,

Explanation

From the above graph, it is shown that the data points do not fall in a straight line.

The maximum data points fall below the quantile-quantile line. The lower and upper portions of the data points fall below the line, and only the middle portion of the data points fall on the line.

So, it can be concluded that the productivity score is not approximately normally distributed.