Finding the Fourth Proportional to 12,981.82, 19,472.72 and 3,121.09

Step by Step Solution

1. Step 1: Write the proportion equation
   12,981.82 : 19,472.72 = 3,121.09 : x
2. Step 2: Convert to fraction form
   12,981.82/19,472.72 = 3,121.09/x
3. Step 3: Cross multiply
   12,981.82x = 19,472.72 × 3,121.09
4. Step 4: Simplify right side
   12,981.82x = 60,776,096.06
5. Step 5: Solve for x
   x = 60,776,096.06/12,981.82
6. Step 6: Final answer
   x = 4,681.63