Finding the Fourth Proportional to 21,840.76, 30,138.16 and 12,768.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,840.76 : 30,138.16 = 12,768.25 : x
2. Step 2: Convert to fraction form
   21,840.76/30,138.16 = 12,768.25/x
3. Step 3: Cross multiply
   21,840.76x = 30,138.16 × 12,768.25
4. Step 4: Simplify right side
   21,840.76x = 384,811,346.89
5. Step 5: Solve for x
   x = 384,811,346.89/21,840.76
6. Step 6: Final answer
   x = 17,618.96