Finding the Fourth Proportional to 2,631.38, 3,945.91 and 986.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,631.38 : 3,945.91 = 986.77 : x
2. Step 2: Convert to fraction form
   2,631.38/3,945.91 = 986.77/x
3. Step 3: Cross multiply
   2,631.38x = 3,945.91 × 986.77
4. Step 4: Simplify right side
   2,631.38x = 3,893,705.61
5. Step 5: Solve for x
   x = 3,893,705.61/2,631.38
6. Step 6: Final answer
   x = 1,479.72