Finding the Fourth Proportional to 39,404.78, 54,378.40 and 21,499.73

Step by Step Solution

1. Step 1: Write the proportion equation
   39,404.78 : 54,378.40 = 21,499.73 : x
2. Step 2: Convert to fraction form
   39,404.78/54,378.40 = 21,499.73/x
3. Step 3: Cross multiply
   39,404.78x = 54,378.40 × 21,499.73
4. Step 4: Simplify right side
   39,404.78x = 1,169,120,917.83
5. Step 5: Solve for x
   x = 1,169,120,917.83/39,404.78
6. Step 6: Final answer
   x = 29,669.52