Finding the Fourth Proportional to 12,673.45, 17,490.86 and 7,640.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,673.45 : 17,490.86 = 7,640.21 : x
2. Step 2: Convert to fraction form
   12,673.45/17,490.86 = 7,640.21/x
3. Step 3: Cross multiply
   12,673.45x = 17,490.86 × 7,640.21
4. Step 4: Simplify right side
   12,673.45x = 133,633,906.31
5. Step 5: Solve for x
   x = 133,633,906.31/12,673.45
6. Step 6: Final answer
   x = 10,544.40