Finding the Fourth Proportional to 128,969.88, 177,986.33 and 72,381.25

Step by Step Solution

1. Step 1: Write the proportion equation
   128,969.88 : 177,986.33 = 72,381.25 : x
2. Step 2: Convert to fraction form
   128,969.88/177,986.33 = 72,381.25/x
3. Step 3: Cross multiply
   128,969.88x = 177,986.33 × 72,381.25
4. Step 4: Simplify right side
   128,969.88x = 12,882,873,048.31
5. Step 5: Solve for x
   x = 12,882,873,048.31/128,969.88
6. Step 6: Final answer
   x = 99,890.56