Finding the Fourth Proportional to 2,146.78, 3,219.34 and 685.14

Step by Step Solution

1. Step 1: Write the proportion equation
   2,146.78 : 3,219.34 = 685.14 : x
2. Step 2: Convert to fraction form
   2,146.78/3,219.34 = 685.14/x
3. Step 3: Cross multiply
   2,146.78x = 3,219.34 × 685.14
4. Step 4: Simplify right side
   2,146.78x = 2,205,698.61
5. Step 5: Solve for x
   x = 2,205,698.61/2,146.78
6. Step 6: Final answer
   x = 1,027.45