Finding the Fourth Proportional to 12,856.39, 17,742.05 and 7,820.83

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856.39 : 17,742.05 = 7,820.83 : x
2. Step 2: Convert to fraction form
   12,856.39/17,742.05 = 7,820.83/x
3. Step 3: Cross multiply
   12,856.39x = 17,742.05 × 7,820.83
4. Step 4: Simplify right side
   12,856.39x = 138,757,429.09
5. Step 5: Solve for x
   x = 138,757,429.09/12,856.39
6. Step 6: Final answer
   x = 10,792.88