Finding the Fourth Proportional to 21,995.79, 30,354.57 and 12,564.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,995.79 : 30,354.57 = 12,564.42 : x
2. Step 2: Convert to fraction form
   21,995.79/30,354.57 = 12,564.42/x
3. Step 3: Cross multiply
   21,995.79x = 30,354.57 × 12,564.42
4. Step 4: Simplify right side
   21,995.79x = 381,387,566.40
5. Step 5: Solve for x
   x = 381,387,566.40/21,995.79
6. Step 6: Final answer
   x = 17,339.12