Finding the Fourth Proportional to 2,018.72, 2,787.42 and 1,577.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,018.72 : 2,787.42 = 1,577.90 : x
2. Step 2: Convert to fraction form
   2,018.72/2,787.42 = 1,577.90/x
3. Step 3: Cross multiply
   2,018.72x = 2,787.42 × 1,577.90
4. Step 4: Simplify right side
   2,018.72x = 4,398,270.02
5. Step 5: Solve for x
   x = 4,398,270.02/2,018.72
6. Step 6: Final answer
   x = 2,178.74