Finding the Fourth Proportional to 39,883.77, 55,039.59 and 21,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   39,883.77 : 55,039.59 = 21,978.72 : x
2. Step 2: Convert to fraction form
   39,883.77/55,039.59 = 21,978.72/x
3. Step 3: Cross multiply
   39,883.77x = 55,039.59 × 21,978.72
4. Step 4: Simplify right side
   39,883.77x = 1,209,699,737.52
5. Step 5: Solve for x
   x = 1,209,699,737.52/39,883.77
6. Step 6: Final answer
   x = 30,330.63