Finding the Fourth Proportional to 12,780.84, 17,639.31 and 7,475.67

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.84 : 17,639.31 = 7,475.67 : x
2. Step 2: Convert to fraction form
   12,780.84/17,639.31 = 7,475.67/x
3. Step 3: Cross multiply
   12,780.84x = 17,639.31 × 7,475.67
4. Step 4: Simplify right side
   12,780.84x = 131,865,660.59
5. Step 5: Solve for x
   x = 131,865,660.59/12,780.84
6. Step 6: Final answer
   x = 10,317.45