Finding the Fourth Proportional to 85,499.60, 128,314.20 and 55,907.60

Step by Step Solution

1. Step 1: Write the proportion equation
   85,499.60 : 128,314.20 = 55,907.60 : x
2. Step 2: Convert to fraction form
   85,499.60/128,314.20 = 55,907.60/x
3. Step 3: Cross multiply
   85,499.60x = 128,314.20 × 55,907.60
4. Step 4: Simplify right side
   85,499.60x = 7,173,738,967.92
5. Step 5: Solve for x
   x = 7,173,738,967.92/85,499.60
6. Step 6: Final answer
   x = 83,903.77