Finding the Fourth Proportional to 128,936.34, 177,933.78 and 72,346.50

Step by Step Solution

1. Step 1: Write the proportion equation
   128,936.34 : 177,933.78 = 72,346.50 : x
2. Step 2: Convert to fraction form
   128,936.34/177,933.78 = 72,346.50/x
3. Step 3: Cross multiply
   128,936.34x = 177,933.78 × 72,346.50
4. Step 4: Simplify right side
   128,936.34x = 12,872,886,214.77
5. Step 5: Solve for x
   x = 12,872,886,214.77/128,936.34
6. Step 6: Final answer
   x = 99,839.09