Finding the Fourth Proportional to 78,728.76, 108,645.10 and 42,920.28

Step by Step Solution

1. Step 1: Write the proportion equation
   78,728.76 : 108,645.10 = 42,920.28 : x
2. Step 2: Convert to fraction form
   78,728.76/108,645.10 = 42,920.28/x
3. Step 3: Cross multiply
   78,728.76x = 108,645.10 × 42,920.28
4. Step 4: Simplify right side
   78,728.76x = 4,663,078,005.33
5. Step 5: Solve for x
   x = 4,663,078,005.33/78,728.76
6. Step 6: Final answer
   x = 59,229.66