Finding the Fourth Proportional to 1,086.31, 1,629.57 and 436.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.31 : 1,629.57 = 436.96 : x
2. Step 2: Convert to fraction form
   1,086.31/1,629.57 = 436.96/x
3. Step 3: Cross multiply
   1,086.31x = 1,629.57 × 436.96
4. Step 4: Simplify right side
   1,086.31x = 712,056.91
5. Step 5: Solve for x
   x = 712,056.91/1,086.31
6. Step 6: Final answer
   x = 655.48