Finding the Fourth Proportional to 1,398.31, 2,098.83 and 851.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.31 : 2,098.83 = 851.56 : x
2. Step 2: Convert to fraction form
   1,398.31/2,098.83 = 851.56/x
3. Step 3: Cross multiply
   1,398.31x = 2,098.83 × 851.56
4. Step 4: Simplify right side
   1,398.31x = 1,787,279.67
5. Step 5: Solve for x
   x = 1,787,279.67/1,398.31
6. Step 6: Final answer
   x = 1,278.17