Finding the Fourth Proportional to 2,139.20, 3,214.50 and 1,152.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.20 : 3,214.50 = 1,152.78 : x
2. Step 2: Convert to fraction form
   2,139.20/3,214.50 = 1,152.78/x
3. Step 3: Cross multiply
   2,139.20x = 3,214.50 × 1,152.78
4. Step 4: Simplify right side
   2,139.20x = 3,705,595.24
5. Step 5: Solve for x
   x = 3,705,595.24/2,139.20
6. Step 6: Final answer
   x = 1,732.23