Finding the Fourth Proportional to 30,530.79, 42,108.80 and 20,456.01

Step by Step Solution

1. Step 1: Write the proportion equation
   30,530.79 : 42,108.80 = 20,456.01 : x
2. Step 2: Convert to fraction form
   30,530.79/42,108.80 = 20,456.01/x
3. Step 3: Cross multiply
   30,530.79x = 42,108.80 × 20,456.01
4. Step 4: Simplify right side
   30,530.79x = 861,377,931.61
5. Step 5: Solve for x
   x = 861,377,931.61/30,530.79
6. Step 6: Final answer
   x = 28,213.42