A Traffic Engineer Wanted to Study the Delays in Traffic

Multiple Choice

A traffic engineer wanted to study the delays in traffic movement at three traffic signal locations, as measured by the number of seconds before the first car clears the intersection. The engineer selected three locations randomly from all the signals with a similar amount of traffic and number of lanes, and similar turn and signal patterns. The engineer collected the following data on eight randomly chosen days. The engineer obtains a statistics book and, after investigating, decides that analysis of variance is the appropriate method for his problem. What conditions have to hold for analysis of variance to be valid?

A) ₁ = ₂ = ₃
B) ₁ > 2₂ > 2₃
C) s₁ = s₂ = s₃
D) s₁ > 2s₂ > 2s₃