Finding the Fourth Proportional to 12,810.50, 17,678.49 and 7,221.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,810.50 : 17,678.49 = 7,221.50 : x
2. Step 2: Convert to fraction form
   12,810.50/17,678.49 = 7,221.50/x
3. Step 3: Cross multiply
   12,810.50x = 17,678.49 × 7,221.50
4. Step 4: Simplify right side
   12,810.50x = 127,665,215.54
5. Step 5: Solve for x
   x = 127,665,215.54/12,810.50
6. Step 6: Final answer
   x = 9,965.67