Finding the Fourth Proportional to 12,834.02, 19,218.90 and 8,139.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,834.02 : 19,218.90 = 8,139.80 : x
2. Step 2: Convert to fraction form
   12,834.02/19,218.90 = 8,139.80/x
3. Step 3: Cross multiply
   12,834.02x = 19,218.90 × 8,139.80
4. Step 4: Simplify right side
   12,834.02x = 156,438,002.22
5. Step 5: Solve for x
   x = 156,438,002.22/12,834.02
6. Step 6: Final answer
   x = 12,189.32