Finding the Fourth Proportional to 1,384.72, 1,910.88 and 825.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.72 : 1,910.88 = 825.28 : x
2. Step 2: Convert to fraction form
   1,384.72/1,910.88 = 825.28/x
3. Step 3: Cross multiply
   1,384.72x = 1,910.88 × 825.28
4. Step 4: Simplify right side
   1,384.72x = 1,577,011.05
5. Step 5: Solve for x
   x = 1,577,011.05/1,384.72
6. Step 6: Final answer
   x = 1,138.87