Question 1202518
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If you need to find the exact formula, to be used repeatedly, relating distance and gallons of gas, then you want to find the constant of proportionality, as shown in the responses from the other tutors.<br>
However, if you are only required to solve this particular problem, doing the work to find that constant is extra unnecessary effort.<br>
Since the variation is direct, the factor by which the distance changes will be the same as the factor by which the number of gallons of gas changes.  So the answer is the result of a single simple calculation:<br>
{{{207*(13/9)=(207*13)/9=(207/9)*13=23*13=299}}}<br>
ANSWER: 299 miles<br>