Finding the Fourth Proportional to 1,385.08, 1,911.66 and 787.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.08 : 1,911.66 = 787.57 : x
2. Step 2: Convert to fraction form
   1,385.08/1,911.66 = 787.57/x
3. Step 3: Cross multiply
   1,385.08x = 1,911.66 × 787.57
4. Step 4: Simplify right side
   1,385.08x = 1,505,566.07
5. Step 5: Solve for x
   x = 1,505,566.07/1,385.08
6. Step 6: Final answer
   x = 1,086.99