Finding the Fourth Proportional to 78,720.69, 108,635.70 and 42,910.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78,720.69 : 108,635.70 = 42,910.72 : x
2. Step 2: Convert to fraction form
   78,720.69/108,635.70 = 42,910.72/x
3. Step 3: Cross multiply
   78,720.69x = 108,635.70 × 42,910.72
4. Step 4: Simplify right side
   78,720.69x = 4,661,636,104.70
5. Step 5: Solve for x
   x = 4,661,636,104.70/78,720.69
6. Step 6: Final answer
   x = 59,217.42