The question asks which of the following is not a unit rate. A unit rate compares a quantity to one unit of another quantity, generally involving a "per 1" concept.

Let's analyze each option:

1. 0.3 miles / 1 minute - This is a unit rate because it expresses miles per 1 minute.
2. 1 minute / 3 feet - This is not a unit rate because it doesn't simplify to a "per 1" format; it compares 1 minute to 3 feet rather than to 1 foot or 1 minute.
3. 0.75 hour / 1 game - This is a unit rate because it expresses hours per 1 game.
4. 4 dogs / 1 yard - This is a unit rate as it expresses dogs per 1 yard.

Answer: The option that is not a unit rate is 1 minute / 3 feet.

Would you like further details on unit rates, or have any other questions?

Here are some additional questions that might help you understand this concept better:

1. What is the difference between a rate and a unit rate?
2. How do you convert a rate to a unit rate?
3. Why is “1 minute per 3 feet” not considered a unit rate?
4. Can unit rates have non-integer values?
5. How can unit rates be applied in real-life scenarios?

Tip: When determining a unit rate, always look for a comparison to a single unit, such as "per 1 unit" of the other quantity.