If after being dealt 4 hearts out of a deck of 52 cards, it means that there are only (52 - 4) or 48 cards left to draw from.
This is the new sample space.
There are 13 hearts in a deck of cards. But you have been dealt 4 out of the 13. Meaning you have 9 more hearts to choose from. This is the possible outcome
Therefore, the probabiity of you getting another heart will be:

Therefore, the final answer is:

= 0.188( to nearest thousandth)