Finding the Fourth Proportional to 1,355.15, 1,870.00 and 787.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.15 : 1,870.00 = 787.89 : x
2. Step 2: Convert to fraction form
   1,355.15/1,870.00 = 787.89/x
3. Step 3: Cross multiply
   1,355.15x = 1,870.00 × 787.89
4. Step 4: Simplify right side
   1,355.15x = 1,473,363.77
5. Step 5: Solve for x
   x = 1,473,363.77/1,355.15
6. Step 6: Final answer
   x = 1,087.24