Answer:

In #3, you can see that the real subject is the word 'proceeds', and that the words 'from the sale of every automobile sold at tonight's charity event' are only intervening or a prepositional phrase, and therefore, you can eliminate them. So the sentence will be going 'The proceeds goes...', as the word 'proceeds' is itself plural, 'goes' should be 'go', the base form or the plural form. In #4, you can see that the real subject in that sentence is none other than the word 'one', and the words 'in every four Americans' are just what you call 'intervening words' or a prepositional phrase (as it starts with a preposition 'in'). So the sentence will go 'One agree...', which is definitely wrong. The word 'one' here is also itself singular. Hence, it requires a singular verb, too. Thus, the word 'agree' should be 'agrees' so that the subject and the verb will be agreeing with one another. It is important to remember these rules, and remember that the subject and the verb should agree.