We are given : Giannina's painting sold for over $300.
Let the price of Geannina's painting in dollars = P.
Note: We are given a word " over " in above statement.
Over word represents more than. So, we need to use more than inequality symbol to write an inequality for the given statement.
Let us rephrase the given statement.
" Price P is greater than $300".
Now, we can write an inequality :
P> 300.
Therefore, the required inequality for given statement is P > 300.