Finding the Fourth Proportional to 8,429.67, 12,640.43 and 4,920.71

Step by Step Solution

1. Step 1: Write the proportion equation
   8,429.67 : 12,640.43 = 4,920.71 : x
2. Step 2: Convert to fraction form
   8,429.67/12,640.43 = 4,920.71/x
3. Step 3: Cross multiply
   8,429.67x = 12,640.43 × 4,920.71
4. Step 4: Simplify right side
   8,429.67x = 62,199,802.50
5. Step 5: Solve for x
   x = 62,199,802.50/8,429.67
6. Step 6: Final answer
   x = 7,378.68