Finding the Fourth Proportional to 2,086.39, 3,130.61 and 990.46

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.39 : 3,130.61 = 990.46 : x
2. Step 2: Convert to fraction form
   2,086.39/3,130.61 = 990.46/x
3. Step 3: Cross multiply
   2,086.39x = 3,130.61 × 990.46
4. Step 4: Simplify right side
   2,086.39x = 3,100,743.98
5. Step 5: Solve for x
   x = 3,100,743.98/2,086.39
6. Step 6: Final answer
   x = 1,486.18