Finding the Fourth Proportional to 2,085.27, 3,128.03 and 990.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.27 : 3,128.03 = 990.69 : x
2. Step 2: Convert to fraction form
   2,085.27/3,128.03 = 990.69/x
3. Step 3: Cross multiply
   2,085.27x = 3,128.03 × 990.69
4. Step 4: Simplify right side
   2,085.27x = 3,098,908.04
5. Step 5: Solve for x
   x = 3,098,908.04/2,085.27
6. Step 6: Final answer
   x = 1,486.09