Finding the Fourth Proportional to 12,636.16, 17,440.32 and 7,857.76

Step by Step Solution

1. Step 1: Write the proportion equation
   12,636.16 : 17,440.32 = 7,857.76 : x
2. Step 2: Convert to fraction form
   12,636.16/17,440.32 = 7,857.76/x
3. Step 3: Cross multiply
   12,636.16x = 17,440.32 × 7,857.76
4. Step 4: Simplify right side
   12,636.16x = 137,041,848.88
5. Step 5: Solve for x
   x = 137,041,848.88/12,636.16
6. Step 6: Final answer
   x = 10,845.21