Finding the Fourth Proportional to 9,321.28, 12,863.42 and 5,072.37

Step by Step Solution

1. Step 1: Write the proportion equation
   9,321.28 : 12,863.42 = 5,072.37 : x
2. Step 2: Convert to fraction form
   9,321.28/12,863.42 = 5,072.37/x
3. Step 3: Cross multiply
   9,321.28x = 12,863.42 × 5,072.37
4. Step 4: Simplify right side
   9,321.28x = 65,248,025.71
5. Step 5: Solve for x
   x = 65,248,025.71/9,321.28
6. Step 6: Final answer
   x = 6,999.90