Finding the Fourth Proportional to 120,996.72, 166,830.84 and 78,539.76

Step by Step Solution

1. Step 1: Write the proportion equation
   120,996.72 : 166,830.84 = 78,539.76 : x
2. Step 2: Convert to fraction form
   120,996.72/166,830.84 = 78,539.76/x
3. Step 3: Cross multiply
   120,996.72x = 166,830.84 × 78,539.76
4. Step 4: Simplify right side
   120,996.72x = 13,102,854,134.20
5. Step 5: Solve for x
   x = 13,102,854,134.20/120,996.72
6. Step 6: Final answer
   x = 108,290.99