Answer
a) A student in my school has visited North Dakota.
b) Every student in my school has visited North Dakota.
c) There does not exist a student in my school who has visited North Dakota.
d) There is a student in my school who has not visited North Dakota.
e) None of the students in my school have visited North Dakota.
f) Every one of the students in my school has not visited North Dakota.
Work Step by Step
Here, we represent $\exists$, $\forall$, $\neg \exists$, and $\neg \forall$ in words - formulations such as "there exists," "every," "there does not exist," and "none," respectively - then substitute our given statements for $N(x)$ and $x$.
a) A student in my school has visited North Dakota.
b) Every student in my school has visited North Dakota.
c) There does not exist a student in my school who has visited North Dakota.
d) There is a student in my school who has not visited North Dakota.
e) None of the students in my school have visited North Dakota.
f) Every one of the students in my school has not visited North Dakota.
