Finding the Fourth Proportional to 39,483.72, 54,487.41 and 21,578.72

Step by Step Solution

1. Step 1: Write the proportion equation
   39,483.72 : 54,487.41 = 21,578.72 : x
2. Step 2: Convert to fraction form
   39,483.72/54,487.41 = 21,578.72/x
3. Step 3: Cross multiply
   39,483.72x = 54,487.41 × 21,578.72
4. Step 4: Simplify right side
   39,483.72x = 1,175,768,517.05
5. Step 5: Solve for x
   x = 1,175,768,517.05/39,483.72
6. Step 6: Final answer
   x = 29,778.56