Finding the Fourth Proportional to 1,116.87, 1,674.18 and 385.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.87 : 1,674.18 = 385.89 : x
2. Step 2: Convert to fraction form
   1,116.87/1,674.18 = 385.89/x
3. Step 3: Cross multiply
   1,116.87x = 1,674.18 × 385.89
4. Step 4: Simplify right side
   1,116.87x = 646,049.32
5. Step 5: Solve for x
   x = 646,049.32/1,116.87
6. Step 6: Final answer
   x = 578.45