Finding the Fourth Proportional to 21,928.78, 30,259.88 and 12,974.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,928.78 : 30,259.88 = 12,974.72 : x
2. Step 2: Convert to fraction form
   21,928.78/30,259.88 = 12,974.72/x
3. Step 3: Cross multiply
   21,928.78x = 30,259.88 × 12,974.72
4. Step 4: Simplify right side
   21,928.78x = 392,613,430.37
5. Step 5: Solve for x
   x = 392,613,430.37/21,928.78
6. Step 6: Final answer
   x = 17,904.03