Finding the Fourth Proportional to 1,116.63, 1,674.47 and 386.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.63 : 1,674.47 = 386.10 : x
2. Step 2: Convert to fraction form
   1,116.63/1,674.47 = 386.10/x
3. Step 3: Cross multiply
   1,116.63x = 1,674.47 × 386.10
4. Step 4: Simplify right side
   1,116.63x = 646,513.83
5. Step 5: Solve for x
   x = 646,513.83/1,116.63
6. Step 6: Final answer
   x = 578.99