In the equation \( C = 18 + 4x \), \( C \) represents the total cost, \( 18 \) represents a fixed cost (like a base fee), and \( 4x \) represents the cost that varies based on the number of books \( x \) that Tatiana purchases, where \( 4 \) is the coefficient of \( x \).
The coefficient \( 4 \) indicates that for each book purchased, she spends an additional $4.
Therefore, the correct interpretation of the coefficient \( 4 \) is:
Statement #1: Tatiana spent $4.00 per book at the public library.
Statement #2 is incorrect because it references the fixed cost, which is $18.00, not the per book fee.
So, the answer is:
Statement #1 could be a correct interpretation of the coefficient of a term.