Finding the Fourth Proportional to 78,689.55, 108,590.16 and 42,879.85

Step by Step Solution

1. Step 1: Write the proportion equation
   78,689.55 : 108,590.16 = 42,879.85 : x
2. Step 2: Convert to fraction form
   78,689.55/108,590.16 = 42,879.85/x
3. Step 3: Cross multiply
   78,689.55x = 108,590.16 × 42,879.85
4. Step 4: Simplify right side
   78,689.55x = 4,656,329,772.28
5. Step 5: Solve for x
   x = 4,656,329,772.28/78,689.55
6. Step 6: Final answer
   x = 59,173.42