Finding the Fourth Proportional to 9,139.50, 12,611.97 and 5,105.57

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.50 : 12,611.97 = 5,105.57 : x
2. Step 2: Convert to fraction form
   9,139.50/12,611.97 = 5,105.57/x
3. Step 3: Cross multiply
   9,139.50x = 12,611.97 × 5,105.57
4. Step 4: Simplify right side
   9,139.50x = 64,391,232.61
5. Step 5: Solve for x
   x = 64,391,232.61/9,139.50
6. Step 6: Final answer
   x = 7,045.38