Finding the Fourth Proportional to 1,116.15, 1,674.23 and 385.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.15 : 1,674.23 = 385.72 : x
2. Step 2: Convert to fraction form
   1,116.15/1,674.23 = 385.72/x
3. Step 3: Cross multiply
   1,116.15x = 1,674.23 × 385.72
4. Step 4: Simplify right side
   1,116.15x = 645,784.00
5. Step 5: Solve for x
   x = 645,784.00/1,116.15
6. Step 6: Final answer
   x = 578.58