Which of the following has the lowest expected return to the investor?

Achecklists should be based on past

Issued to the joint planning and execution community (jpec) initiates the development of coas; it also requests that the supported ccdr submit a commander's estimate of the situation with a recommended coa to resolve the situation (joint force command and staff participation in the joint operation planning and execution system, page 10)

The answer here, x=7, is not in the interval that you selected in the previous part. what is wrong with the work shown above?