To find out how much time Maria has to spend on each part of the test, we need to divide the total time she has by the number of parts.
Maria has a total of \( \frac{3}{4} \) of an hour to complete 4 parts.
We divide \( \frac{3}{4} \) by 4:
\[ \text{Time per part} = \frac{3}{4} \div 4 \]
Dividing by 4 is the same as multiplying by \( \frac{1}{4} \):
\[ \text{Time per part} = \frac{3}{4} \times \frac{1}{4} = \frac{3 \times 1}{4 \times 4} = \frac{3}{16} \]
So, Maria has \( \frac{3}{16} \) of an hour to spend on each part of the test.