Finding the Fourth Proportional to 78,139.24, 117,136.60 and 30,780.12

Step by Step Solution

1. Step 1: Write the proportion equation
   78,139.24 : 117,136.60 = 30,780.12 : x
2. Step 2: Convert to fraction form
   78,139.24/117,136.60 = 30,780.12/x
3. Step 3: Cross multiply
   78,139.24x = 117,136.60 × 30,780.12
4. Step 4: Simplify right side
   78,139.24x = 3,605,478,604.39
5. Step 5: Solve for x
   x = 3,605,478,604.39/78,139.24
6. Step 6: Final answer
   x = 46,141.72