Finding the Fourth Proportional to 8,865.72, 12,234.06 and 5,139

Step by Step Solution

1. Step 1: Write the proportion equation
   8,865.72 : 12,234.06 = 5,139 : x
2. Step 2: Convert to fraction form
   8,865.72/12,234.06 = 5,139/x
3. Step 3: Cross multiply
   8,865.72x = 12,234.06 × 5,139
4. Step 4: Simplify right side
   8,865.72x = 62,870,834.34
5. Step 5: Solve for x
   x = 62,870,834.34/8,865.72
6. Step 6: Final answer
   x = 7,091.45