Finding the Fourth Proportional to 21,710.72, 32,606.20 and 12,999.17

Step by Step Solution

1. Step 1: Write the proportion equation
   21,710.72 : 32,606.20 = 12,999.17 : x
2. Step 2: Convert to fraction form
   21,710.72/32,606.20 = 12,999.17/x
3. Step 3: Cross multiply
   21,710.72x = 32,606.20 × 12,999.17
4. Step 4: Simplify right side
   21,710.72x = 423,853,536.85
5. Step 5: Solve for x
   x = 423,853,536.85/21,710.72
6. Step 6: Final answer
   x = 19,522.78