Finding the Fourth Proportional to 2,081.80, 3,123.77 and 985.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,081.80 : 3,123.77 = 985.87 : x
2. Step 2: Convert to fraction form
   2,081.80/3,123.77 = 985.87/x
3. Step 3: Cross multiply
   2,081.80x = 3,123.77 × 985.87
4. Step 4: Simplify right side
   2,081.80x = 3,079,630.11
5. Step 5: Solve for x
   x = 3,079,630.11/2,081.80
6. Step 6: Final answer
   x = 1,479.31