Finding the Fourth Proportional to 1,116.72, 1,675.26 and 386.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.72 : 1,675.26 = 386.10 : x
2. Step 2: Convert to fraction form
   1,116.72/1,675.26 = 386.10/x
3. Step 3: Cross multiply
   1,116.72x = 1,675.26 × 386.10
4. Step 4: Simplify right side
   1,116.72x = 646,817.89
5. Step 5: Solve for x
   x = 646,817.89/1,116.72
6. Step 6: Final answer
   x = 579.21