Finding the Fourth Proportional to 1,086.08, 1,628.72 and 436.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.08 : 1,628.72 = 436.80 : x
2. Step 2: Convert to fraction form
   1,086.08/1,628.72 = 436.80/x
3. Step 3: Cross multiply
   1,086.08x = 1,628.72 × 436.80
4. Step 4: Simplify right side
   1,086.08x = 711,424.90
5. Step 5: Solve for x
   x = 711,424.90/1,086.08
6. Step 6: Final answer
   x = 655.04