Finding the Fourth Proportional to 1,085.67, 1,629.72 and 436.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.67 : 1,629.72 = 436.86 : x
2. Step 2: Convert to fraction form
   1,085.67/1,629.72 = 436.86/x
3. Step 3: Cross multiply
   1,085.67x = 1,629.72 × 436.86
4. Step 4: Simplify right side
   1,085.67x = 711,959.48
5. Step 5: Solve for x
   x = 711,959.48/1,085.67
6. Step 6: Final answer
   x = 655.78