Finding the Fourth Proportional to 12,778.84, 17,634.42 and 7,189.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,778.84 : 17,634.42 = 7,189.72 : x
2. Step 2: Convert to fraction form
   12,778.84/17,634.42 = 7,189.72/x
3. Step 3: Cross multiply
   12,778.84x = 17,634.42 × 7,189.72
4. Step 4: Simplify right side
   12,778.84x = 126,786,542.16
5. Step 5: Solve for x
   x = 126,786,542.16/12,778.84
6. Step 6: Final answer
   x = 9,921.60