Finding the Fourth Proportional to 1,787.15, 2,466.20 and 990.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,787.15 : 2,466.20 = 990.50 : x
2. Step 2: Convert to fraction form
   1,787.15/2,466.20 = 990.50/x
3. Step 3: Cross multiply
   1,787.15x = 2,466.20 × 990.50
4. Step 4: Simplify right side
   1,787.15x = 2,442,753.82
5. Step 5: Solve for x
   x = 2,442,753.82/1,787.15
6. Step 6: Final answer
   x = 1,366.85