Finding the Fourth Proportional to 1,109.10, 1,663.52 and 287.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.10 : 1,663.52 = 287.31 : x
2. Step 2: Convert to fraction form
   1,109.10/1,663.52 = 287.31/x
3. Step 3: Cross multiply
   1,109.10x = 1,663.52 × 287.31
4. Step 4: Simplify right side
   1,109.10x = 477,945.93
5. Step 5: Solve for x
   x = 477,945.93/1,109.10
6. Step 6: Final answer
   x = 430.93