2/3in=9mi
?in=21mi
we can set up a ratio and proportion, but I would fix that fractions because they tend to be messy
2/3in=9mi
multiply both sides by 3
2in=27mi
so now we have
2in:28mi=?in:21mi
[tex]\frac{2in}{28mi}=\frac{?in}{21mi}[/tex]
multiply both sides by 21mi
the miles cancel and we get
[tex]\frac{42in}{28}=?in[/tex]
1.5in=?in
1.5 inches represents 21 miles
