To find out what percent of the total cost the grading comes to, we need to divide the cost of the grading by the total cost of the house and then multiply by 100.
Let's calculate the percent:
\text{{Percentage}} = \frac{{\text{{Cost of grading}}}}{{\text{{Total cost of house}}}} \times 100
Substituting in the given values:
\text{{Percentage}} = \frac{{3974.75}}{{159775}} \times 100
Now let's calculate this:
\text{{Percentage}} = \frac{{3974.75}}{{159775}} \times 100 \approx 2.49\%
Answer: The grading on the $159,775 house comes to approximately 2.49% of the total cost.