Finding the Fourth Proportional to 2,139.46, 3,209.50 and 906.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.46 : 3,209.50 = 906.10 : x
2. Step 2: Convert to fraction form
   2,139.46/3,209.50 = 906.10/x
3. Step 3: Cross multiply
   2,139.46x = 3,209.50 × 906.10
4. Step 4: Simplify right side
   2,139.46x = 2,908,127.95
5. Step 5: Solve for x
   x = 2,908,127.95/2,139.46
6. Step 6: Final answer
   x = 1,359.28