Final answer:
The value of the macro variable rate is the string 4+3.
Step-by-step explanation:
The value of the macro variable rate after the statement is processed is 4+3. The macro variable rate is assigned the value 4+3 because the statement %let rate=4+3; is assigning the string 4+3 to the macro variable rate. This means that the value of rate will be the literal string 4+3 and not the result of evaluating the expression 4+3.