Finding the Fourth Proportional to 1,109.29, 1,663.59 and 800.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.29 : 1,663.59 = 800.20 : x
2. Step 2: Convert to fraction form
   1,109.29/1,663.59 = 800.20/x
3. Step 3: Cross multiply
   1,109.29x = 1,663.59 × 800.20
4. Step 4: Simplify right side
   1,109.29x = 1,331,204.72
5. Step 5: Solve for x
   x = 1,331,204.72/1,109.29
6. Step 6: Final answer
   x = 1,200.05