Finding the Fourth Proportional to 78,198.72, 107,913.60 and 42,388.80

Step by Step Solution

1. Step 1: Write the proportion equation
   78,198.72 : 107,913.60 = 42,388.80 : x
2. Step 2: Convert to fraction form
   78,198.72/107,913.60 = 42,388.80/x
3. Step 3: Cross multiply
   78,198.72x = 107,913.60 × 42,388.80
4. Step 4: Simplify right side
   78,198.72x = 4,574,328,007.68
5. Step 5: Solve for x
   x = 4,574,328,007.68/78,198.72
6. Step 6: Final answer
   x = 58,496.20