Finding the Fourth Proportional to 99,664.34, 149,557.55 and 39,721.57

Step by Step Solution

1. Step 1: Write the proportion equation
   99,664.34 : 149,557.55 = 39,721.57 : x
2. Step 2: Convert to fraction form
   99,664.34/149,557.55 = 39,721.57/x
3. Step 3: Cross multiply
   99,664.34x = 149,557.55 × 39,721.57
4. Step 4: Simplify right side
   99,664.34x = 5,940,661,071.83
5. Step 5: Solve for x
   x = 5,940,661,071.83/99,664.34
6. Step 6: Final answer
   x = 59,606.69