Finding the Fourth Proportional to 12,870.20, 17,761.07 and 7,834.63

Step by Step Solution

1. Step 1: Write the proportion equation
   12,870.20 : 17,761.07 = 7,834.63 : x
2. Step 2: Convert to fraction form
   12,870.20/17,761.07 = 7,834.63/x
3. Step 3: Cross multiply
   12,870.20x = 17,761.07 × 7,834.63
4. Step 4: Simplify right side
   12,870.20x = 139,151,411.85
5. Step 5: Solve for x
   x = 139,151,411.85/12,870.20
6. Step 6: Final answer
   x = 10,811.91