Finding the Fourth Proportional to 1,146.57, 1,719.86 and 280.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,146.57 : 1,719.86 = 280.88 : x
2. Step 2: Convert to fraction form
   1,146.57/1,719.86 = 280.88/x
3. Step 3: Cross multiply
   1,146.57x = 1,719.86 × 280.88
4. Step 4: Simplify right side
   1,146.57x = 483,064.27
5. Step 5: Solve for x
   x = 483,064.27/1,146.57
6. Step 6: Final answer
   x = 421.31