Answer
There is no difference between the measures of centres because they are equal.
Work Step by Step
The mean can be counted by summing all the data and dividing it by the number of data: Jefferson Valley: $\frac{6.5+6.6+6.7+6.8+7.1+7.3+7.4+7.7+7.7+7.7}{10}=7.15$, Residence: $\frac{4.2+5.4+5.8+6.2+6.7+7.7+7.7+8.5+9.3+10}{10}=7.15$. The median is the average of the 1 or 2 (here 2) middle data: Jefferson Valley:(7.1+7.3)/2=7.2, for African American drivers:(6.7+7.7)/2=7.2. The African American drivers appear to speed more because their mean is more. There is no difference between the measures of centres because they are equal.
