Finding the Fourth Proportional to 12,816.21, 17,686.50 and 7,439.82

Step by Step Solution

1. Step 1: Write the proportion equation
   12,816.21 : 17,686.50 = 7,439.82 : x
2. Step 2: Convert to fraction form
   12,816.21/17,686.50 = 7,439.82/x
3. Step 3: Cross multiply
   12,816.21x = 17,686.50 × 7,439.82
4. Step 4: Simplify right side
   12,816.21x = 131,584,376.43
5. Step 5: Solve for x
   x = 131,584,376.43/12,816.21
6. Step 6: Final answer
   x = 10,267.03