Finding the Fourth Proportional to 128,646.50, 177,532.18 and 72,059.10

Step by Step Solution

1. Step 1: Write the proportion equation
   128,646.50 : 177,532.18 = 72,059.10 : x
2. Step 2: Convert to fraction form
   128,646.50/177,532.18 = 72,059.10/x
3. Step 3: Cross multiply
   128,646.50x = 177,532.18 × 72,059.10
4. Step 4: Simplify right side
   128,646.50x = 12,792,809,111.84
5. Step 5: Solve for x
   x = 12,792,809,111.84/128,646.50
6. Step 6: Final answer
   x = 99,441.56