Finding the Fourth Proportional to 2,138.40, 2,950.72 and 1,206.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,138.40 : 2,950.72 = 1,206.72 : x
2. Step 2: Convert to fraction form
   2,138.40/2,950.72 = 1,206.72/x
3. Step 3: Cross multiply
   2,138.40x = 2,950.72 × 1,206.72
4. Step 4: Simplify right side
   2,138.40x = 3,560,692.84
5. Step 5: Solve for x
   x = 3,560,692.84/2,138.40
6. Step 6: Final answer
   x = 1,665.12