Finding the Fourth Proportional to 31,012.08, 42,812.56 and 20,993.52

Step by Step Solution

1. Step 1: Write the proportion equation
   31,012.08 : 42,812.56 = 20,993.52 : x
2. Step 2: Convert to fraction form
   31,012.08/42,812.56 = 20,993.52/x
3. Step 3: Cross multiply
   31,012.08x = 42,812.56 × 20,993.52
4. Step 4: Simplify right side
   31,012.08x = 898,786,334.61
5. Step 5: Solve for x
   x = 898,786,334.61/31,012.08
6. Step 6: Final answer
   x = 28,981.81