Finding the Fourth Proportional to 1,109.84, 1,665.72 and 426.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.84 : 1,665.72 = 426.32 : x
2. Step 2: Convert to fraction form
   1,109.84/1,665.72 = 426.32/x
3. Step 3: Cross multiply
   1,109.84x = 1,665.72 × 426.32
4. Step 4: Simplify right side
   1,109.84x = 710,129.75
5. Step 5: Solve for x
   x = 710,129.75/1,109.84
6. Step 6: Final answer
   x = 639.85