Finding the Fourth Proportional to 39,633.42, 54,693.39 and 21,728.55

Step by Step Solution

1. Step 1: Write the proportion equation
   39,633.42 : 54,693.39 = 21,728.55 : x
2. Step 2: Convert to fraction form
   39,633.42/54,693.39 = 21,728.55/x
3. Step 3: Cross multiply
   39,633.42x = 54,693.39 × 21,728.55
4. Step 4: Simplify right side
   39,633.42x = 1,188,408,059.28
5. Step 5: Solve for x
   x = 1,188,408,059.28/39,633.42
6. Step 6: Final answer
   x = 29,985.00