Finding the Fourth Proportional to 12,769.72, 17,630.94 and 9,780.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,769.72 : 17,630.94 = 9,780.28 : x
2. Step 2: Convert to fraction form
   12,769.72/17,630.94 = 9,780.28/x
3. Step 3: Cross multiply
   12,769.72x = 17,630.94 × 9,780.28
4. Step 4: Simplify right side
   12,769.72x = 172,435,529.86
5. Step 5: Solve for x
   x = 172,435,529.86/12,769.72
6. Step 6: Final answer
   x = 13,503.47