Finding the Fourth Proportional to 139,411.32, 208,836.31 and 64,428.20

Step by Step Solution

1. Step 1: Write the proportion equation
   139,411.32 : 208,836.31 = 64,428.20 : x
2. Step 2: Convert to fraction form
   139,411.32/208,836.31 = 64,428.20/x
3. Step 3: Cross multiply
   139,411.32x = 208,836.31 × 64,428.20
4. Step 4: Simplify right side
   139,411.32x = 13,454,947,547.94
5. Step 5: Solve for x
   x = 13,454,947,547.94/139,411.32
6. Step 6: Final answer
   x = 96,512.59