Finding the Fourth Proportional to 1,086.05, 1,628.67 and 436.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.05 : 1,628.67 = 436.57 : x
2. Step 2: Convert to fraction form
   1,086.05/1,628.67 = 436.57/x
3. Step 3: Cross multiply
   1,086.05x = 1,628.67 × 436.57
4. Step 4: Simplify right side
   1,086.05x = 711,020.32
5. Step 5: Solve for x
   x = 711,020.32/1,086.05
6. Step 6: Final answer
   x = 654.68