Finding the Fourth Proportional to 115,705.74, 159,688.71 and 64,721.30

Step by Step Solution

1. Step 1: Write the proportion equation
   115,705.74 : 159,688.71 = 64,721.30 : x
2. Step 2: Convert to fraction form
   115,705.74/159,688.71 = 64,721.30/x
3. Step 3: Cross multiply
   115,705.74x = 159,688.71 × 64,721.30
4. Step 4: Simplify right side
   115,705.74x = 10,335,260,906.52
5. Step 5: Solve for x
   x = 10,335,260,906.52/115,705.74
6. Step 6: Final answer
   x = 89,323.67