Finding the Fourth Proportional to 10,139.72, 15,211.67 and 3,119.31

Step by Step Solution

1. Step 1: Write the proportion equation
   10,139.72 : 15,211.67 = 3,119.31 : x
2. Step 2: Convert to fraction form
   10,139.72/15,211.67 = 3,119.31/x
3. Step 3: Cross multiply
   10,139.72x = 15,211.67 × 3,119.31
4. Step 4: Simplify right side
   10,139.72x = 47,449,898.75
5. Step 5: Solve for x
   x = 47,449,898.75/10,139.72
6. Step 6: Final answer
   x = 4,679.61