Finding the Fourth Proportional to 42,789.54, 64,156.98 and 20,558.70

Step by Step Solution

1. Step 1: Write the proportion equation
   42,789.54 : 64,156.98 = 20,558.70 : x
2. Step 2: Convert to fraction form
   42,789.54/64,156.98 = 20,558.70/x
3. Step 3: Cross multiply
   42,789.54x = 64,156.98 × 20,558.70
4. Step 4: Simplify right side
   42,789.54x = 1,318,984,104.73
5. Step 5: Solve for x
   x = 1,318,984,104.73/42,789.54
6. Step 6: Final answer
   x = 30,824.92