Finding the Fourth Proportional to 1,863.20, 2,792.88 and 986.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,863.20 : 2,792.88 = 986.72 : x
2. Step 2: Convert to fraction form
   1,863.20/2,792.88 = 986.72/x
3. Step 3: Cross multiply
   1,863.20x = 2,792.88 × 986.72
4. Step 4: Simplify right side
   1,863.20x = 2,755,790.55
5. Step 5: Solve for x
   x = 2,755,790.55/1,863.20
6. Step 6: Final answer
   x = 1,479.06