Finding the Fourth Proportional to 20,978.66, 31,460.42 and 7,124.42

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.66 : 31,460.42 = 7,124.42 : x
2. Step 2: Convert to fraction form
   20,978.66/31,460.42 = 7,124.42/x
3. Step 3: Cross multiply
   20,978.66x = 31,460.42 × 7,124.42
4. Step 4: Simplify right side
   20,978.66x = 224,137,105.97
5. Step 5: Solve for x
   x = 224,137,105.97/20,978.66
6. Step 6: Final answer
   x = 10,684.06