Answer:
Null hypothesis; H0: μ1 = μ2
Alternative hypothesis; Ha: μ1 > μ2
Step-by-step explanation:
We are told that the telraffic was experiencing an average of 20 accidents per week.
Thus, μ = 20
We are told that the council decided to try to reduce the number of accidents.
Thus defining the hypothesis, we have;
Null hypothesis; H0: μ1 = μ2
Alternative hypothesis; Ha: μ1 > μ2