Finding the Fourth Proportional to 14,128.78, 19,496.94 and 7,840.78

Step by Step Solution

1. Step 1: Write the proportion equation
   14,128.78 : 19,496.94 = 7,840.78 : x
2. Step 2: Convert to fraction form
   14,128.78/19,496.94 = 7,840.78/x
3. Step 3: Cross multiply
   14,128.78x = 19,496.94 × 7,840.78
4. Step 4: Simplify right side
   14,128.78x = 152,871,217.21
5. Step 5: Solve for x
   x = 152,871,217.21/14,128.78
6. Step 6: Final answer
   x = 10,819.85