Finding the Fourth Proportional to 9,139.72, 12,612.76 and 5,162.12

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.72 : 12,612.76 = 5,162.12 : x
2. Step 2: Convert to fraction form
   9,139.72/12,612.76 = 5,162.12/x
3. Step 3: Cross multiply
   9,139.72x = 12,612.76 × 5,162.12
4. Step 4: Simplify right side
   9,139.72x = 65,108,580.65
5. Step 5: Solve for x
   x = 65,108,580.65/9,139.72
6. Step 6: Final answer
   x = 7,123.70