Finding the Fourth Proportional to 13,131.36, 18,120.96 and 7,542.72

Step by Step Solution

1. Step 1: Write the proportion equation
   13,131.36 : 18,120.96 = 7,542.72 : x
2. Step 2: Convert to fraction form
   13,131.36/18,120.96 = 7,542.72/x
3. Step 3: Cross multiply
   13,131.36x = 18,120.96 × 7,542.72
4. Step 4: Simplify right side
   13,131.36x = 136,681,327.41
5. Step 5: Solve for x
   x = 136,681,327.41/13,131.36
6. Step 6: Final answer
   x = 10,408.77