Finding the Fourth Proportional to 21,728.30, 30,009.72 and 14,642.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,728.30 : 30,009.72 = 14,642.42 : x
2. Step 2: Convert to fraction form
   21,728.30/30,009.72 = 14,642.42/x
3. Step 3: Cross multiply
   21,728.30x = 30,009.72 × 14,642.42
4. Step 4: Simplify right side
   21,728.30x = 439,414,924.32
5. Step 5: Solve for x
   x = 439,414,924.32/21,728.30
6. Step 6: Final answer
   x = 20,223.16