Finding the Fourth Proportional to 39,883.31, 55,039.33 and 21,978.96

Step by Step Solution

1. Step 1: Write the proportion equation
   39,883.31 : 55,039.33 = 21,978.96 : x
2. Step 2: Convert to fraction form
   39,883.31/55,039.33 = 21,978.96/x
3. Step 3: Cross multiply
   39,883.31x = 55,039.33 × 21,978.96
4. Step 4: Simplify right side
   39,883.31x = 1,209,707,287.44
5. Step 5: Solve for x
   x = 1,209,707,287.44/39,883.31
6. Step 6: Final answer
   x = 30,331.16