Finding the Fourth Proportional to 1,128.72, 1,692.52 and 512.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.72 : 1,692.52 = 512.16 : x
2. Step 2: Convert to fraction form
   1,128.72/1,692.52 = 512.16/x
3. Step 3: Cross multiply
   1,128.72x = 1,692.52 × 512.16
4. Step 4: Simplify right side
   1,128.72x = 866,841.04
5. Step 5: Solve for x
   x = 866,841.04/1,128.72
6. Step 6: Final answer
   x = 767.99