Translate the following arguments into standard-form categorical syllogisms, then use Venn diagrams or the rules for syllogisms to determine whether each is valid or invalid. See Section 4.7 for help...

Translate the following arguments into standard-form categorical syllogisms, then use Venn diagrams or the rules for syllogisms to determine whether each is valid or invalid. See Section 4.7 for help with the translation.

According to surveys, there are college students who think that Africa is in North America. But anyone who thinks that has no knowledge of geography. It follows that there are college students who have no knowledge of geography.