Finding the Fourth Proportional to 21,478.24, 29,656.56 and 13,929.85

Step by Step Solution

1. Step 1: Write the proportion equation
   21,478.24 : 29,656.56 = 13,929.85 : x
2. Step 2: Convert to fraction form
   21,478.24/29,656.56 = 13,929.85/x
3. Step 3: Cross multiply
   21,478.24x = 29,656.56 × 13,929.85
4. Step 4: Simplify right side
   21,478.24x = 413,111,432.32
5. Step 5: Solve for x
   x = 413,111,432.32/21,478.24
6. Step 6: Final answer
   x = 19,233.95