Monitoring organizational e-mails. One way to measure the level of communication at a company is by the number of daily e-mails sent. The communication network at Enron (just prior to the scandal which led to the company’s demise) was studied in the Journal of Quality Technology (Vol. 52, 2020). The researchers focused on the daily number of “mutual dyads,” where a mutual dyad is back-and-forth communication between two departments or two employees. Assume that the researchers sampled 100,000 emails per day for 100 consecutive days and then calculated the proportion of mutual dyads found each day. A relatively high or low proportion may be an indication of an unexpected or unusual event (e.g., a hostile takeover, a threat of a merger). Data on the daily number of dyads found (based on information provided in the journal article) are shown at the bottom of the page.

a. Construct a p-chart for the daily proportion of mutual dyads.

b. What does it indicate about the stability of the level of communication at Enron? Explain.

c. Identify any days that may involve special causes of variation.