Finding the Fourth Proportional to 128,839.86, 177,847.38 and 75,141.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,839.86 : 177,847.38 = 75,141.72 : x
2. Step 2: Convert to fraction form
   128,839.86/177,847.38 = 75,141.72/x
3. Step 3: Cross multiply
   128,839.86x = 177,847.38 × 75,141.72
4. Step 4: Simplify right side
   128,839.86x = 13,363,758,030.69
5. Step 5: Solve for x
   x = 13,363,758,030.69/128,839.86
6. Step 6: Final answer
   x = 103,723.79