Finding the Fourth Proportional to 1,100.72, 1,649.60 and 553.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,100.72 : 1,649.60 = 553.30 : x
2. Step 2: Convert to fraction form
   1,100.72/1,649.60 = 553.30/x
3. Step 3: Cross multiply
   1,100.72x = 1,649.60 × 553.30
4. Step 4: Simplify right side
   1,100.72x = 912,721.62
5. Step 5: Solve for x
   x = 912,721.62/1,100.72
6. Step 6: Final answer
   x = 829.20