The article "Analysis of Unwanted Fire Alarm: Case Study" (W. Chow, N. Fong, and C. Ho, Journal of Architectural Engineering, 1999:62-65) presents a count of the number of false alarms at several sites. The numbers of false alarms each month, divided into those with known causes and those with unknown causes, are given in the following table. Can you conclude that the proportion of false alarms whose cause is known differs from month to month?

Transcribed Image Text:

Month 1 2 3 4 5 6 7 8 9 10 11 12 Known 20 13 21 26 23 18 14 10 20 20 18 14 Unknown 12 2 16 12 22 30 32 32 14 16 10 12