Finding the Fourth Proportional to 21,061.14, 31,591.70 and 5,478.77

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.14 : 31,591.70 = 5,478.77 : x
2. Step 2: Convert to fraction form
   21,061.14/31,591.70 = 5,478.77/x
3. Step 3: Cross multiply
   21,061.14x = 31,591.70 × 5,478.77
4. Step 4: Simplify right side
   21,061.14x = 173,083,472.86
5. Step 5: Solve for x
   x = 173,083,472.86/21,061.14
6. Step 6: Final answer
   x = 8,218.14