Finding the Fourth Proportional to 1,085.42, 1,626.78 and 435.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.42 : 1,626.78 = 435.80 : x
2. Step 2: Convert to fraction form
   1,085.42/1,626.78 = 435.80/x
3. Step 3: Cross multiply
   1,085.42x = 1,626.78 × 435.80
4. Step 4: Simplify right side
   1,085.42x = 708,950.72
5. Step 5: Solve for x
   x = 708,950.72/1,085.42
6. Step 6: Final answer
   x = 653.16