Finding the Fourth Proportional to 1,108.72, 1,662.72 and 378.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,108.72 : 1,662.72 = 378.28 : x
2. Step 2: Convert to fraction form
   1,108.72/1,662.72 = 378.28/x
3. Step 3: Cross multiply
   1,108.72x = 1,662.72 × 378.28
4. Step 4: Simplify right side
   1,108.72x = 628,973.72
5. Step 5: Solve for x
   x = 628,973.72/1,108.72
6. Step 6: Final answer
   x = 567.30