Finding the Fourth Proportional to 128,555.59, 177,406.72 and 78,254.59

Step by Step Solution

1. Step 1: Write the proportion equation
   128,555.59 : 177,406.72 = 78,254.59 : x
2. Step 2: Convert to fraction form
   128,555.59/177,406.72 = 78,254.59/x
3. Step 3: Cross multiply
   128,555.59x = 177,406.72 × 78,254.59
4. Step 4: Simplify right side
   128,555.59x = 13,882,890,136.84
5. Step 5: Solve for x
   x = 13,882,890,136.84/128,555.59
6. Step 6: Final answer
   x = 107,991.34