Finding the Fourth Proportional to 2,630.42, 3,945.84 and 781.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,630.42 : 3,945.84 = 781.40 : x
2. Step 2: Convert to fraction form
   2,630.42/3,945.84 = 781.40/x
3. Step 3: Cross multiply
   2,630.42x = 3,945.84 × 781.40
4. Step 4: Simplify right side
   2,630.42x = 3,083,279.38
5. Step 5: Solve for x
   x = 3,083,279.38/2,630.42
6. Step 6: Final answer
   x = 1,172.16