Finding the Fourth Proportional to 21,776, 30,056 and 12,949.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,776 : 30,056 = 12,949.12 : x
2. Step 2: Convert to fraction form
   21,776/30,056 = 12,949.12/x
3. Step 3: Cross multiply
   21,776x = 30,056 × 12,949.12
4. Step 4: Simplify right side
   21,776x = 389,198,750.72
5. Step 5: Solve for x
   x = 389,198,750.72/21,776
6. Step 6: Final answer
   x = 17,872.83