Finding the Fourth Proportional to 1,072.18, 1,606.72 and 455.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,072.18 : 1,606.72 = 455.55 : x
2. Step 2: Convert to fraction form
   1,072.18/1,606.72 = 455.55/x
3. Step 3: Cross multiply
   1,072.18x = 1,606.72 × 455.55
4. Step 4: Simplify right side
   1,072.18x = 731,941.30
5. Step 5: Solve for x
   x = 731,941.30/1,072.18
6. Step 6: Final answer
   x = 682.67