Question

A scientist has a hypothesis that as the number of police cars is increased on a roadway, the proportion of cars speeding decreases. He finds that at police car level X1 (one police car per 100 miles), the proportion of cars speeding is p hat equals 0.83. At police car level X2 (one police car per 50 miles), the proportion of cars speeding is p hat equals 0.61. At police car level X3 (one police car per 25 miles), the proportion of cars speeding is p hat equals 0.39. Should the hypothesis be rejected or should it fail to be rejected?

Answer 1

Rejected, because the data do not support the hypothesis that as the number of police cars per mile increases, the proportion of cars speeding decreases
Fail to be rejected, because this was an experimental study and the hypothesis is always confirmed in this form of study
Fail to be rejected, because the proportion of drivers speeding goes down as the number of police cars per mile on a roadway increases
Rejected, because one of the limits of an experimental study such as this is that causation cannot be made between the variables