Answer:
1. Nominal data 2. Responses here can't be classified as interval or nominal or ordinal data 3. Responses here can't be classified as interval or nominal or ordinal data 4. nominal
Step-by-step explanation:
1. Heidi's favorite brand of tenis balls is only a "label" in the set of brands that can be regarded. So, because we are dealing with names or "labels" we should classify responses here as nominal data.
2. Possible values for the number of cars in a parking lot are 0, 1, 2, 3, 4,... Besides we can say that 4 cars is twice than 2 cars, and exist a true zero. We can't say that responses here correspond to interval data, in fact, we can say that responses here correspond to the kind of data called ratio data.
3. You can spend zero hours in your homework, so, there exists an absolute zero, besides, to say that you spend 4 hours in your homework is twice that if you spend 2 hours in your homework is meaningful. We can't classify responses here as interval data or ordinal or nominal. We can classify responses here as ratio data.
4. There are only two different responses here, i.e., You are a US citizen or You are not a US citizen. We are dealing with "labels" again, and in general, we can't say there is a better response or stablish an order.
; where 
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