Given that Colleen rode 5 miles on her bicycle on an average time per mile of 6.2 minutes.
Given that her times for the first 4 miles were 4.8 minutes, 5.2 minutes . 7.1 minutes, 7.2 minutes.
Let her time for the last mile be x minutes, then
[tex] \frac{4.8+5.2+7.1+7.2+x}{5} =6.2 \\ \\ \Rightarrow24.3+x=5(6.2)=31 \\ \\ x=31-24.3=6.7[/tex]
Therefore, her time for the last mile is 6.7 minutes
