Finding the Fourth Proportional to 1,376.75, 1,899.90 and 787.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,376.75 : 1,899.90 = 787.25 : x
2. Step 2: Convert to fraction form
   1,376.75/1,899.90 = 787.25/x
3. Step 3: Cross multiply
   1,376.75x = 1,899.90 × 787.25
4. Step 4: Simplify right side
   1,376.75x = 1,495,686.78
5. Step 5: Solve for x
   x = 1,495,686.78/1,376.75
6. Step 6: Final answer
   x = 1,086.39