Finding the Fourth Proportional to 1,109.59, 1,664.49 and 287.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.59 : 1,664.49 = 287.86 : x
2. Step 2: Convert to fraction form
   1,109.59/1,664.49 = 287.86/x
3. Step 3: Cross multiply
   1,109.59x = 1,664.49 × 287.86
4. Step 4: Simplify right side
   1,109.59x = 479,138.65
5. Step 5: Solve for x
   x = 479,138.65/1,109.59
6. Step 6: Final answer
   x = 431.82