Finding the Fourth Proportional to 30,786.89, 42,485.82 and 16,639.70

Step by Step Solution

1. Step 1: Write the proportion equation
   30,786.89 : 42,485.82 = 16,639.70 : x
2. Step 2: Convert to fraction form
   30,786.89/42,485.82 = 16,639.70/x
3. Step 3: Cross multiply
   30,786.89x = 42,485.82 × 16,639.70
4. Step 4: Simplify right side
   30,786.89x = 706,951,086.62
5. Step 5: Solve for x
   x = 706,951,086.62/30,786.89
6. Step 6: Final answer
   x = 22,962.74