Finding the Fourth Proportional to 1,085.83, 1,628.81 and 436.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.83 : 1,628.81 = 436.56 : x
2. Step 2: Convert to fraction form
   1,085.83/1,628.81 = 436.56/x
3. Step 3: Cross multiply
   1,085.83x = 1,628.81 × 436.56
4. Step 4: Simplify right side
   1,085.83x = 711,071.11
5. Step 5: Solve for x
   x = 711,071.11/1,085.83
6. Step 6: Final answer
   x = 654.87