Finding the Fourth Proportional to 1,345.15, 1,856.37 and 785.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.15 : 1,856.37 = 785.70 : x
2. Step 2: Convert to fraction form
   1,345.15/1,856.37 = 785.70/x
3. Step 3: Cross multiply
   1,345.15x = 1,856.37 × 785.70
4. Step 4: Simplify right side
   1,345.15x = 1,458,549.91
5. Step 5: Solve for x
   x = 1,458,549.91/1,345.15
6. Step 6: Final answer
   x = 1,084.30