Finding the Fourth Proportional to 1,653.31, 2,280.78 and 990.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,653.31 : 2,280.78 = 990.04 : x
2. Step 2: Convert to fraction form
   1,653.31/2,280.78 = 990.04/x
3. Step 3: Cross multiply
   1,653.31x = 2,280.78 × 990.04
4. Step 4: Simplify right side
   1,653.31x = 2,258,052.03
5. Step 5: Solve for x
   x = 2,258,052.03/1,653.31
6. Step 6: Final answer
   x = 1,365.78