Finding the Fourth Proportional to 1,426.37, 2,139.56 and 645.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,426.37 : 2,139.56 = 645.94 : x
2. Step 2: Convert to fraction form
   1,426.37/2,139.56 = 645.94/x
3. Step 3: Cross multiply
   1,426.37x = 2,139.56 × 645.94
4. Step 4: Simplify right side
   1,426.37x = 1,382,027.39
5. Step 5: Solve for x
   x = 1,382,027.39/1,426.37
6. Step 6: Final answer
   x = 968.91