Finding the Fourth Proportional to 80,128.88, 120,156.60 and 42,679.16

Step by Step Solution

1. Step 1: Write the proportion equation
   80,128.88 : 120,156.60 = 42,679.16 : x
2. Step 2: Convert to fraction form
   80,128.88/120,156.60 = 42,679.16/x
3. Step 3: Cross multiply
   80,128.88x = 120,156.60 × 42,679.16
4. Step 4: Simplify right side
   80,128.88x = 5,128,182,756.46
5. Step 5: Solve for x
   x = 5,128,182,756.46/80,128.88
6. Step 6: Final answer
   x = 63,999.18