Finding the Fourth Proportional to 2,139.75, 2,952.86 and 1,256.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.75 : 2,952.86 = 1,256.45 : x
2. Step 2: Convert to fraction form
   2,139.75/2,952.86 = 1,256.45/x
3. Step 3: Cross multiply
   2,139.75x = 2,952.86 × 1,256.45
4. Step 4: Simplify right side
   2,139.75x = 3,710,099.90
5. Step 5: Solve for x
   x = 3,710,099.90/2,139.75
6. Step 6: Final answer
   x = 1,733.89