Finding the Fourth Proportional to 12,645.81, 17,447.56 and 8,172.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,645.81 : 17,447.56 = 8,172.18 : x
2. Step 2: Convert to fraction form
   12,645.81/17,447.56 = 8,172.18/x
3. Step 3: Cross multiply
   12,645.81x = 17,447.56 × 8,172.18
4. Step 4: Simplify right side
   12,645.81x = 142,584,600.88
5. Step 5: Solve for x
   x = 142,584,600.88/12,645.81
6. Step 6: Final answer
   x = 11,275.24