A large geographical area, such as a state

If you're asking about telephone area codes, 750 is not currently used in the North American Numbering Plan.

toll-free telephone numbers in the North American Numbering Plan. Area code 877 (Russia), Republic of Adygea.

I recommend the World Telephone Numbering Guide.

Unlike the Pacific islands that are owned by the United States, Fiji is not part of the North American Numbering Plan, so it doesn't have an "area code". Its country code is +679.