Finding the Fourth Proportional to 2,628.83, 3,940.80 and 986.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,628.83 : 3,940.80 = 986.45 : x
2. Step 2: Convert to fraction form
   2,628.83/3,940.80 = 986.45/x
3. Step 3: Cross multiply
   2,628.83x = 3,940.80 × 986.45
4. Step 4: Simplify right side
   2,628.83x = 3,887,382.46
5. Step 5: Solve for x
   x = 3,887,382.46/2,628.83
6. Step 6: Final answer
   x = 1,478.75