Here's why:
* Subject Pronoun: "I" is the correct subject pronoun to use when referring to yourself in this context.
* Subject-Verb Agreement: The verb "are going" agrees with the plural subject "Franci and I."
However, it's important to note that the sentence lacks context. It's unclear:
* What kind of party?
* Where is the party?
* When is the party?
Adding details would make the sentence more informative. For example:
* "Franci and I are going to a costume party."
* "Franci and I are going to the party at Sarah's house."
* "Franci and I are going to the party tomorrow night."