Finding the Fourth Proportional to 2,139.58, 2,949.10 and 1,431.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.58 : 2,949.10 = 1,431.18 : x
2. Step 2: Convert to fraction form
   2,139.58/2,949.10 = 1,431.18/x
3. Step 3: Cross multiply
   2,139.58x = 2,949.10 × 1,431.18
4. Step 4: Simplify right side
   2,139.58x = 4,220,692.94
5. Step 5: Solve for x
   x = 4,220,692.94/2,139.58
6. Step 6: Final answer
   x = 1,972.67