Finding the Fourth Proportional to 128,643.10, 177,527.47 and 78,342.10

Step by Step Solution

1. Step 1: Write the proportion equation
   128,643.10 : 177,527.47 = 78,342.10 : x
2. Step 2: Convert to fraction form
   128,643.10/177,527.47 = 78,342.10/x
3. Step 3: Cross multiply
   128,643.10x = 177,527.47 × 78,342.10
4. Step 4: Simplify right side
   128,643.10x = 13,907,873,919.85
5. Step 5: Solve for x
   x = 13,907,873,919.85/128,643.10
6. Step 6: Final answer
   x = 108,112.09