Answer:
5
Step-by-step explanation:
We want the average arrests to be 4. It can be done by calculating the average between the average arrests and arrests during the 5th week, so we get:
Avg(1,2,3,4,5) = (Avg(1,2,3,4) + A(5)) / 2
Where Avg(x) is the average of arrests in given weeks, and A(x) is the number of arrests in a given week.
Solving for A(5) => A(5) = 2*Avg(1,2,3,4,5) - Avg(1,2,3,4) = 2 * 4 - 3 = 8-3 = 5