Answer:
56°
Explanation:
First calculate 

The interplanar spacing can be calculated from:

The diffraction angle is determined from:

Solve for 

The diffraction angle is:

I think that it might represent Velocity
To start, 1 cubic centimeter = 1 milliliter, so now you have 1.11g/mL.
Now multiply 1.11 by 387 to get the mass of antifreeze in grams, since the mL is canceled out.
387 mL x 1.11g/mL = 429.57 g