Finding the Fourth Proportional to 2,085.86, 3,128.86 and 787.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.86 : 3,128.86 = 787.02 : x
2. Step 2: Convert to fraction form
   2,085.86/3,128.86 = 787.02/x
3. Step 3: Cross multiply
   2,085.86x = 3,128.86 × 787.02
4. Step 4: Simplify right side
   2,085.86x = 2,462,475.40
5. Step 5: Solve for x
   x = 2,462,475.40/2,085.86
6. Step 6: Final answer
   x = 1,180.56