Finding the Fourth Proportional to 80,320.86, 120,456.38 and 64,488.60

Step by Step Solution

1. Step 1: Write the proportion equation
   80,320.86 : 120,456.38 = 64,488.60 : x
2. Step 2: Convert to fraction form
   80,320.86/120,456.38 = 64,488.60/x
3. Step 3: Cross multiply
   80,320.86x = 120,456.38 × 64,488.60
4. Step 4: Simplify right side
   80,320.86x = 7,768,063,468.49
5. Step 5: Solve for x
   x = 7,768,063,468.49/80,320.86
6. Step 6: Final answer
   x = 96,712.90