Finding the Fourth Proportional to 86,478.96, 128,858.72 and 77,046.50

Step by Step Solution

1. Step 1: Write the proportion equation
   86,478.96 : 128,858.72 = 77,046.50 : x
2. Step 2: Convert to fraction form
   86,478.96/128,858.72 = 77,046.50/x
3. Step 3: Cross multiply
   86,478.96x = 128,858.72 × 77,046.50
4. Step 4: Simplify right side
   86,478.96x = 9,928,113,370.48
5. Step 5: Solve for x
   x = 9,928,113,370.48/86,478.96
6. Step 6: Final answer
   x = 114,803.80