Finding the Fourth Proportional to 12,894.57, 17,789.18 and 7,856.95

Step by Step Solution

1. Step 1: Write the proportion equation
   12,894.57 : 17,789.18 = 7,856.95 : x
2. Step 2: Convert to fraction form
   12,894.57/17,789.18 = 7,856.95/x
3. Step 3: Cross multiply
   12,894.57x = 17,789.18 × 7,856.95
4. Step 4: Simplify right side
   12,894.57x = 139,768,697.80
5. Step 5: Solve for x
   x = 139,768,697.80/12,894.57
6. Step 6: Final answer
   x = 10,839.35