Finding the Fourth Proportional to 30,789.72, 42,489.79 and 16,642.56

Step by Step Solution

1. Step 1: Write the proportion equation
   30,789.72 : 42,489.79 = 16,642.56 : x
2. Step 2: Convert to fraction form
   30,789.72/42,489.79 = 16,642.56/x
3. Step 3: Cross multiply
   30,789.72x = 42,489.79 × 16,642.56
4. Step 4: Simplify right side
   30,789.72x = 707,138,973.79
5. Step 5: Solve for x
   x = 707,138,973.79/30,789.72
6. Step 6: Final answer
   x = 22,966.72