Finding the Fourth Proportional to 139,920.32, 209,802.72 and 56,717.12

Step by Step Solution

1. Step 1: Write the proportion equation
   139,920.32 : 209,802.72 = 56,717.12 : x
2. Step 2: Convert to fraction form
   139,920.32/209,802.72 = 56,717.12/x
3. Step 3: Cross multiply
   139,920.32x = 209,802.72 × 56,717.12
4. Step 4: Simplify right side
   139,920.32x = 11,899,406,046.57
5. Step 5: Solve for x
   x = 11,899,406,046.57/139,920.32
6. Step 6: Final answer
   x = 85,044.16