Finding the Fourth Proportional to 39,728.05, 54,824.50 and 21,823

Step by Step Solution

1. Step 1: Write the proportion equation
   39,728.05 : 54,824.50 = 21,823 : x
2. Step 2: Convert to fraction form
   39,728.05/54,824.50 = 21,823/x
3. Step 3: Cross multiply
   39,728.05x = 54,824.50 × 21,823
4. Step 4: Simplify right side
   39,728.05x = 1,196,435,063.50
5. Step 5: Solve for x
   x = 1,196,435,063.50/39,728.05
6. Step 6: Final answer
   x = 30,115.63