Finding the Fourth Proportional to 21,471.31, 29,638.47 and 12,521.62

Step by Step Solution

1. Step 1: Write the proportion equation
   21,471.31 : 29,638.47 = 12,521.62 : x
2. Step 2: Convert to fraction form
   21,471.31/29,638.47 = 12,521.62/x
3. Step 3: Cross multiply
   21,471.31x = 29,638.47 × 12,521.62
4. Step 4: Simplify right side
   21,471.31x = 371,121,658.72
5. Step 5: Solve for x
   x = 371,121,658.72/21,471.31
6. Step 6: Final answer
   x = 17,284.54