Finding the Fourth Proportional to 9,139.52, 12,611.75 and 5,311.86

Step by Step Solution

1. Step 1: Write the proportion equation
   9,139.52 : 12,611.75 = 5,311.86 : x
2. Step 2: Convert to fraction form
   9,139.52/12,611.75 = 5,311.86/x
3. Step 3: Cross multiply
   9,139.52x = 12,611.75 × 5,311.86
4. Step 4: Simplify right side
   9,139.52x = 66,991,823.80
5. Step 5: Solve for x
   x = 66,991,823.80/9,139.52
6. Step 6: Final answer
   x = 7,329.91