Marcie is 11 years old, which is less than the required age of 12 years to have a social media account.
To express this situation using inequality:
Let \( x \) represent Marcie's age. Then the inequality that compares her age to the age requirement can be written as:
\[ x < 12 \]
This means Marcie's age (11) is less than the required age (12) to have a social media account.