Finding the Fourth Proportional to 21,972.42, 30,321.18 and 12,540.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,972.42 : 30,321.18 = 12,540.60 : x
2. Step 2: Convert to fraction form
   21,972.42/30,321.18 = 12,540.60/x
3. Step 3: Cross multiply
   21,972.42x = 30,321.18 × 12,540.60
4. Step 4: Simplify right side
   21,972.42x = 380,245,789.91
5. Step 5: Solve for x
   x = 380,245,789.91/21,972.42
6. Step 6: Final answer
   x = 17,305.59