Finding the Fourth Proportional to 1,385.76, 2,080.72 and 869.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.76 : 2,080.72 = 869.04 : x
2. Step 2: Convert to fraction form
   1,385.76/2,080.72 = 869.04/x
3. Step 3: Cross multiply
   1,385.76x = 2,080.72 × 869.04
4. Step 4: Simplify right side
   1,385.76x = 1,808,228.91
5. Step 5: Solve for x
   x = 1,808,228.91/1,385.76
6. Step 6: Final answer
   x = 1,304.86