Finding the Fourth Proportional to 2,431.18, 3,647.34 and 787.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,431.18 : 3,647.34 = 787.72 : x
2. Step 2: Convert to fraction form
   2,431.18/3,647.34 = 787.72/x
3. Step 3: Cross multiply
   2,431.18x = 3,647.34 × 787.72
4. Step 4: Simplify right side
   2,431.18x = 2,873,082.66
5. Step 5: Solve for x
   x = 2,873,082.66/2,431.18
6. Step 6: Final answer
   x = 1,181.77