Use the raw data presented in Exercise 6.8 to verify that \(\Sigma(X-\bar{X})=0\).

Exercise 6.8

Given the following data for three projects, perform the complete data analysis as was done for Table 6.2. How would you perform the average cross-check in the cell marked "XXX"?

Table 6.2

Row Row Project January February March April Total Average A 3,000 3,200 3,400 2,800 B 1,200 1,900 2,500 2,400 C 4,500 3,400 4,600 4,200 Column total Column average XXX