Finding the Fourth Proportional to 1,120.43, 1,680.78 and 298.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,120.43 : 1,680.78 = 298.72 : x
2. Step 2: Convert to fraction form
   1,120.43/1,680.78 = 298.72/x
3. Step 3: Cross multiply
   1,120.43x = 1,680.78 × 298.72
4. Step 4: Simplify right side
   1,120.43x = 502,085.82
5. Step 5: Solve for x
   x = 502,085.82/1,120.43
6. Step 6: Final answer
   x = 448.12