Finding the Fourth Proportional to 8,406.82, 12,590.79 and 8,115.22

Step by Step Solution

1. Step 1: Write the proportion equation
   8,406.82 : 12,590.79 = 8,115.22 : x
2. Step 2: Convert to fraction form
   8,406.82/12,590.79 = 8,115.22/x
3. Step 3: Cross multiply
   8,406.82x = 12,590.79 × 8,115.22
4. Step 4: Simplify right side
   8,406.82x = 102,177,030.82
5. Step 5: Solve for x
   x = 102,177,030.82/8,406.82
6. Step 6: Final answer
   x = 12,154.06