Final answer:
Based on the information that Martin can run 1 mile in 7 minutes, the only valid proportion is A) 1 mile / 7 minutes = 1 mile / 7 minutes, which compares the same rate with itself. The other options imply a rate of speed that is inconsistent with the given information and are therefore incorrect.
Step-by-step explanation:
The question involves identifying which proportions are valid based on the information that Martin can run 1 mile in 7 minutes. Proportions compare two ratios to determine if they are equivalent.
- A) 1 mile / 7 minutes = 1 mile / 7 minutes is a valid proportion because it compares the exact same rate with itself, thus it is equivalent.
- B) 1 mile / 1 minute = 7 miles / 7 minutes is not a valid proportion. This would imply that Martin's rate increases to 1 mile per minute which is not the information given.
- C) 7 miles / 1 minute = 1 mile / 7 minutes is not a valid proportion. This would suggest that Martin could run 7 miles in 1 minute, which is inconsistent with the given rate.
- D) 7 miles / 7 minutes = 1 mile / 1 minute is not a valid proportion either because it would mean that Martin is running a mile a minute, which is not true according to the original statement.
Therefore, the only valid proportion from the options given is A) 1 mile / 7 minutes = 1 mile / 7 minutes.