Answer: 
Step-by-step explanation:
1. Based on the information given in the problem, you can draw the right triangle shown in the figure attached.
2. Keeping the informationn given in the problem, you can calculate the angle that the sum makes with the ground (
)as you can see below:

Where:

3. Then:


Answer: the baby weighs 16.5 pounds
-8 the point on the line with Y=4
6506 or 656 is the answer