Finding the Fourth Proportional to 21,538.71, 29,724.11 and 13,042.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,538.71 : 29,724.11 = 13,042.42 : x
2. Step 2: Convert to fraction form
   21,538.71/29,724.11 = 13,042.42/x
3. Step 3: Cross multiply
   21,538.71x = 29,724.11 × 13,042.42
4. Step 4: Simplify right side
   21,538.71x = 387,674,309.50
5. Step 5: Solve for x
   x = 387,674,309.50/21,538.71
6. Step 6: Final answer
   x = 17,998.96