Finding the Fourth Proportional to 2,018.31, 2,784.55 and 1,320.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,018.31 : 2,784.55 = 1,320.09 : x
2. Step 2: Convert to fraction form
   2,018.31/2,784.55 = 1,320.09/x
3. Step 3: Cross multiply
   2,018.31x = 2,784.55 × 1,320.09
4. Step 4: Simplify right side
   2,018.31x = 3,675,856.61
5. Step 5: Solve for x
   x = 3,675,856.61/2,018.31
6. Step 6: Final answer
   x = 1,821.25