Finding the Fourth Proportional to 1,426.84, 2,139.68 and 439.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,426.84 : 2,139.68 = 439.34 : x
2. Step 2: Convert to fraction form
   1,426.84/2,139.68 = 439.34/x
3. Step 3: Cross multiply
   1,426.84x = 2,139.68 × 439.34
4. Step 4: Simplify right side
   1,426.84x = 940,047.01
5. Step 5: Solve for x
   x = 940,047.01/1,426.84
6. Step 6: Final answer
   x = 658.83