Finding the Fourth Proportional to 2,632.48, 3,949.12 and 990.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,632.48 : 3,949.12 = 990.40 : x
2. Step 2: Convert to fraction form
   2,632.48/3,949.12 = 990.40/x
3. Step 3: Cross multiply
   2,632.48x = 3,949.12 × 990.40
4. Step 4: Simplify right side
   2,632.48x = 3,911,208.45
5. Step 5: Solve for x
   x = 3,911,208.45/2,632.48
6. Step 6: Final answer
   x = 1,485.75