Finding the Fourth Proportional to 13,399.72, 18,491.33 and 7,431.26

Step by Step Solution

1. Step 1: Write the proportion equation
   13,399.72 : 18,491.33 = 7,431.26 : x
2. Step 2: Convert to fraction form
   13,399.72/18,491.33 = 7,431.26/x
3. Step 3: Cross multiply
   13,399.72x = 18,491.33 × 7,431.26
4. Step 4: Simplify right side
   13,399.72x = 137,413,751.36
5. Step 5: Solve for x
   x = 137,413,751.36/13,399.72
6. Step 6: Final answer
   x = 10,254.98