Finding the Fourth Proportional to 9,308.86, 12,828.54 and 9,138.10

Step by Step Solution

1. Step 1: Write the proportion equation
   9,308.86 : 12,828.54 = 9,138.10 : x
2. Step 2: Convert to fraction form
   9,308.86/12,828.54 = 9,138.10/x
3. Step 3: Cross multiply
   9,308.86x = 12,828.54 × 9,138.10
4. Step 4: Simplify right side
   9,308.86x = 117,228,481.37
5. Step 5: Solve for x
   x = 117,228,481.37/9,308.86
6. Step 6: Final answer
   x = 12,593.22