1. The problem asks us to write an inequality describing temperatures $t$ at which Mariana wears her winter coat. 2. The condition given is that Mariana wears her coat when the temperature is less than $-4$ degrees Celsius. 3. The inequality representing this condition is: $$t < -4$$ 4. This means Mariana wears her coat for any temperature $t$ that is strictly less than $-4$. 5. There is no graph to plot here, just the inequality statement. Final answer: $$t < -4$$