Finding the Fourth Proportional to 1,128.84, 1,693.41 and 426.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.84 : 1,693.41 = 426.27 : x
2. Step 2: Convert to fraction form
   1,128.84/1,693.41 = 426.27/x
3. Step 3: Cross multiply
   1,128.84x = 1,693.41 × 426.27
4. Step 4: Simplify right side
   1,128.84x = 721,849.88
5. Step 5: Solve for x
   x = 721,849.88/1,128.84
6. Step 6: Final answer
   x = 639.46