Finding the Fourth Proportional to 12,856.32, 17,743.04 and 7,820.90

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856.32 : 17,743.04 = 7,820.90 : x
2. Step 2: Convert to fraction form
   12,856.32/17,743.04 = 7,820.90/x
3. Step 3: Cross multiply
   12,856.32x = 17,743.04 × 7,820.90
4. Step 4: Simplify right side
   12,856.32x = 138,766,541.54
5. Step 5: Solve for x
   x = 138,766,541.54/12,856.32
6. Step 6: Final answer
   x = 10,793.64