Finding the Fourth Proportional to 20,995, 31,460.76 and 12,665.76

Step by Step Solution

1. Step 1: Write the proportion equation
   20,995 : 31,460.76 = 12,665.76 : x
2. Step 2: Convert to fraction form
   20,995/31,460.76 = 12,665.76/x
3. Step 3: Cross multiply
   20,995x = 31,460.76 × 12,665.76
4. Step 4: Simplify right side
   20,995x = 398,474,435.58
5. Step 5: Solve for x
   x = 398,474,435.58/20,995
6. Step 6: Final answer
   x = 18,979.49