9514 1404 393
Answer:
A, C, E
Step-by-step explanation:
The proportional relations on the list are ...
- feet and inches
- flour and bread
- gallons and cost
We often model running distance and time as proportional, but a marathon is a long enough run that speed is rarely constant. It usually decreases over the course, and may increase near the end.
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A relationship is proportional if there is a constant multiplier that relates the output to the input.
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<em>Additional comment</em>
For the relations listed above, the constants are ..
- the conversion factor between feet and inches
- the amount of flour in a bread recipe
- the price of a gallon of gas
For running time and distance, the multiplier is <em>speed</em>. The relation is only proportional if speed is a constant.