Finding the Fourth Proportional to 1,278.76, 1,766.42 and 1,002.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,278.76 : 1,766.42 = 1,002.48 : x
2. Step 2: Convert to fraction form
   1,278.76/1,766.42 = 1,002.48/x
3. Step 3: Cross multiply
   1,278.76x = 1,766.42 × 1,002.48
4. Step 4: Simplify right side
   1,278.76x = 1,770,800.72
5. Step 5: Solve for x
   x = 1,770,800.72/1,278.76
6. Step 6: Final answer
   x = 1,384.78