Finding the Fourth Proportional to 20,460.59, 30,684.72 and 13,440.32

Step by Step Solution

1. Step 1: Write the proportion equation
   20,460.59 : 30,684.72 = 13,440.32 : x
2. Step 2: Convert to fraction form
   20,460.59/30,684.72 = 13,440.32/x
3. Step 3: Cross multiply
   20,460.59x = 30,684.72 × 13,440.32
4. Step 4: Simplify right side
   20,460.59x = 412,412,467.96
5. Step 5: Solve for x
   x = 412,412,467.96/20,460.59
6. Step 6: Final answer
   x = 20,156.43