Finding the Fourth Proportional to 12,423, 17,135.06 and 8,172.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,423 : 17,135.06 = 8,172.72 : x
2. Step 2: Convert to fraction form
   12,423/17,135.06 = 8,172.72/x
3. Step 3: Cross multiply
   12,423x = 17,135.06 × 8,172.72
4. Step 4: Simplify right side
   12,423x = 140,040,047.56
5. Step 5: Solve for x
   x = 140,040,047.56/12,423
6. Step 6: Final answer
   x = 11,272.64