Finding the Fourth Proportional to 78,391.14, 108,178.79 and 42,581.40

Step by Step Solution

1. Step 1: Write the proportion equation
   78,391.14 : 108,178.79 = 42,581.40 : x
2. Step 2: Convert to fraction form
   78,391.14/108,178.79 = 42,581.40/x
3. Step 3: Cross multiply
   78,391.14x = 108,178.79 × 42,581.40
4. Step 4: Simplify right side
   78,391.14x = 4,606,403,949.45
5. Step 5: Solve for x
   x = 4,606,403,949.45/78,391.14
6. Step 6: Final answer
   x = 58,761.79