Finding the Fourth Proportional to 1,345.40, 1,856.46 and 785.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.40 : 1,856.46 = 785.79 : x
2. Step 2: Convert to fraction form
   1,345.40/1,856.46 = 785.79/x
3. Step 3: Cross multiply
   1,345.40x = 1,856.46 × 785.79
4. Step 4: Simplify right side
   1,345.40x = 1,458,787.70
5. Step 5: Solve for x
   x = 1,458,787.70/1,345.40
6. Step 6: Final answer
   x = 1,084.28