Finding the Fourth Proportional to 8,405.32, 12,588.54 and 8,113.72

Step by Step Solution

1. Step 1: Write the proportion equation
   8,405.32 : 12,588.54 = 8,113.72 : x
2. Step 2: Convert to fraction form
   8,405.32/12,588.54 = 8,113.72/x
3. Step 3: Cross multiply
   8,405.32x = 12,588.54 × 8,113.72
4. Step 4: Simplify right side
   8,405.32x = 102,139,888.77
5. Step 5: Solve for x
   x = 102,139,888.77/8,405.32
6. Step 6: Final answer
   x = 12,151.81