Finding the Fourth Proportional to 13,406.72, 18,503.48 and 7,440.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,406.72 : 18,503.48 = 7,440.31 : x
2. Step 2: Convert to fraction form
   13,406.72/18,503.48 = 7,440.31/x
3. Step 3: Cross multiply
   13,406.72x = 18,503.48 × 7,440.31
4. Step 4: Simplify right side
   13,406.72x = 137,671,534.76
5. Step 5: Solve for x
   x = 137,671,534.76/13,406.72
6. Step 6: Final answer
   x = 10,268.85