Finding the Fourth Proportional to 128,643.50, 177,528.04 and 72,056.10

Step by Step Solution

1. Step 1: Write the proportion equation
   128,643.50 : 177,528.04 = 72,056.10 : x
2. Step 2: Convert to fraction form
   128,643.50/177,528.04 = 72,056.10/x
3. Step 3: Cross multiply
   128,643.50x = 177,528.04 × 72,056.10
4. Step 4: Simplify right side
   128,643.50x = 12,791,978,203.04
5. Step 5: Solve for x
   x = 12,791,978,203.04/128,643.50
6. Step 6: Final answer
   x = 99,437.42