Answer:
The average speed of Sebastian is 3 miles per hour.
Solution:
Given, In
hours, Sebastian can walk 4 1/2 miles.
we have to find What is his average speed in hours per mile
We know that, average speed
![=\frac{\text {total distance walked}}{\text {total time taken}}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/15g914ld8qsp8yxgbfd9lw9ub2w65tgf3v.png)
In our problem, total distance travelled =
![4 (1)/(2) \text { miles }=(4 * 2+1)/(2) \text { miles }=(9)/(2) \text { miles. }](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5z2qg6wds3cxshayjppkjgh64b1d5rh205.png)
![\text { And, total time taken }=1 (1)/(2) \text { hours }=(1 * 2+1)/(2) \text { hours }=(3)/(2) \text { miles. }](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dv60r6a4trfy9ev5gr2y7polbha3gilcl5.png)
Now, average speed of Sebastian
![=((9)/(2))/((3)/(2))=(9)/(2) * (2)/(3)=(9)/(3)=3](https://img.qammunity.org/2020/formulas/mathematics/middle-school/3kdy0pjsx626h2ywbghxsl943r4m5lu9pz.png)
Hence, the average speed of Sebastian is 3 miles per hour.