Finding the Fourth Proportional to 30,971.62, 42,758.56 and 20,392

Step by Step Solution

1. Step 1: Write the proportion equation
   30,971.62 : 42,758.56 = 20,392 : x
2. Step 2: Convert to fraction form
   30,971.62/42,758.56 = 20,392/x
3. Step 3: Cross multiply
   30,971.62x = 42,758.56 × 20,392
4. Step 4: Simplify right side
   30,971.62x = 871,932,555.52
5. Step 5: Solve for x
   x = 871,932,555.52/30,971.62
6. Step 6: Final answer
   x = 28,152.63