This is a problem on hypothesis testing on the difference of two dependent means. To solve for this one, the difference for each pair should be solved.
After it, the mean and standard deviation of the differences should also be calculated. Then, we state the null and alternative hypotheses.
The null hypothesis is
The alternative hypothesis is
These are the required hypotheses <span>to see whether the number of graffiti incidents declined. </span>
After it, the mean and standard deviation of the differences should also be calculated. Then, we state the null and alternative hypotheses.
The null hypothesis is
The alternative hypothesis is
These are the required hypotheses <span>to see whether the number of graffiti incidents declined. </span>