Finding the Fourth Proportional to 13,144.31, 18,136.88 and 12,479.32

Step by Step Solution

1. Step 1: Write the proportion equation
   13,144.31 : 18,136.88 = 12,479.32 : x
2. Step 2: Convert to fraction form
   13,144.31/18,136.88 = 12,479.32/x
3. Step 3: Cross multiply
   13,144.31x = 18,136.88 × 12,479.32
4. Step 4: Simplify right side
   13,144.31x = 226,335,834.37
5. Step 5: Solve for x
   x = 226,335,834.37/13,144.31
6. Step 6: Final answer
   x = 17,219.30