Finding the Fourth Proportional to 1,138.52, 1,704.34 and 809.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,138.52 : 1,704.34 = 809.60 : x
2. Step 2: Convert to fraction form
   1,138.52/1,704.34 = 809.60/x
3. Step 3: Cross multiply
   1,138.52x = 1,704.34 × 809.60
4. Step 4: Simplify right side
   1,138.52x = 1,379,826.15
5. Step 5: Solve for x
   x = 1,379,826.15/1,138.52
6. Step 6: Final answer
   x = 1,211.94