The historical on-time percentage for Amtrak's Sunset Limited is 10 percent. In July, the train was on

Question:

The historical on-time percentage for Amtrak's Sunset Limited is 10 percent. In July, the train was on time 0 times in 31 runs. At the .10 level of significance, has the on-time percentage fallen? Explain clearly. Use Excel to calculate the cumulative binomial probability P(X ≤ 0 | n = 31, π = .10).