Finding the Fourth Proportional to 2,086.16, 3,129.74 and 989.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.16 : 3,129.74 = 989.96 : x
2. Step 2: Convert to fraction form
   2,086.16/3,129.74 = 989.96/x
3. Step 3: Cross multiply
   2,086.16x = 3,129.74 × 989.96
4. Step 4: Simplify right side
   2,086.16x = 3,098,312.46
5. Step 5: Solve for x
   x = 3,098,312.46/2,086.16
6. Step 6: Final answer
   x = 1,485.17