Finding the Fourth Proportional to 21,928.56, 30,259.17 and 12,974.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,928.56 : 30,259.17 = 12,974.28 : x
2. Step 2: Convert to fraction form
   21,928.56/30,259.17 = 12,974.28/x
3. Step 3: Cross multiply
   21,928.56x = 30,259.17 × 12,974.28
4. Step 4: Simplify right side
   21,928.56x = 392,590,944.15
5. Step 5: Solve for x
   x = 392,590,944.15/21,928.56
6. Step 6: Final answer
   x = 17,903.18