I need to translate the given statement into propositional logic using the propositions provided.
To use the wireless network in the airport you must pay the daily fee unless you are a subscriber to the service. Express your answer in terms of
$\;w:\;$ “You can use the wireless network in the airport,”
$\;d:\;$ “You pay the daily fee,” and
$\;s:\;$ “You are a subscriber to the service.”
$$\text{If }\; w, \;\text{then}\; (d \;\text{or}\; s),\;\text{ which is equivalent to }\; w {\it \text{ only if}}\;\; (d \;\text{or}\; s).\;$$ and can be expressed symbolically as the proposition: $$w \rightarrow(d \lor s)$$
Since you used the tag "predicate calculus" and if you mean for the variables to represent predicates, then define a constant to represent "you": $y:= \text{ you}$
$$w(y) \rightarrow (d(y) \lor s(y))$$
Or if we are stating a universal policy, applying to the domain of all airport visitors, then we have $$\forall x\,\Big(w(x) \rightarrow (d(x)\lor s(x))\Big)$$
This might make more sense if we consider the logically equivalent contrapositive of the quantified expression:
$$\forall x\,\Big(\lnot(d(x) \lor s(x)) \rightarrow \lnot w(x)\Big)\equiv \forall x\,\Big((\lnot d(x) \land \lnot s(x)) \rightarrow \lnot w(x)\Big)$$
If you do not pay the daily fee and you are not a subscriber, then you cannot use the wireless service in the airport.