Finding the Fourth Proportional to 78,728.18, 108,644.58 and 42,918.08

Step by Step Solution

1. Step 1: Write the proportion equation
   78,728.18 : 108,644.58 = 42,918.08 : x
2. Step 2: Convert to fraction form
   78,728.18/108,644.58 = 42,918.08/x
3. Step 3: Cross multiply
   78,728.18x = 108,644.58 × 42,918.08
4. Step 4: Simplify right side
   78,728.18x = 4,662,816,776.01
5. Step 5: Solve for x
   x = 4,662,816,776.01/78,728.18
6. Step 6: Final answer
   x = 59,226.78