Finding the Fourth Proportional to 2,155.50, 3,234.72 and 787.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.50 : 3,234.72 = 787.50 : x
2. Step 2: Convert to fraction form
   2,155.50/3,234.72 = 787.50/x
3. Step 3: Cross multiply
   2,155.50x = 3,234.72 × 787.50
4. Step 4: Simplify right side
   2,155.50x = 2,547,342
5. Step 5: Solve for x
   x = 2,547,342/2,155.50
6. Step 6: Final answer
   x = 1,181.79