Finding the Fourth Proportional to 1,116.06, 1,673.86 and 385.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.06 : 1,673.86 = 385.71 : x
2. Step 2: Convert to fraction form
   1,116.06/1,673.86 = 385.71/x
3. Step 3: Cross multiply
   1,116.06x = 1,673.86 × 385.71
4. Step 4: Simplify right side
   1,116.06x = 645,624.54
5. Step 5: Solve for x
   x = 645,624.54/1,116.06
6. Step 6: Final answer
   x = 578.49