Finding the Fourth Proportional to 2,630.06, 3,945.15 and 781.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,630.06 : 3,945.15 = 781.20 : x
2. Step 2: Convert to fraction form
   2,630.06/3,945.15 = 781.20/x
3. Step 3: Cross multiply
   2,630.06x = 3,945.15 × 781.20
4. Step 4: Simplify right side
   2,630.06x = 3,081,951.18
5. Step 5: Solve for x
   x = 3,081,951.18/2,630.06
6. Step 6: Final answer
   x = 1,171.82