Finding the Fourth Proportional to 1,208.42, 1,811.46 and 386.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,208.42 : 1,811.46 = 386.10 : x
2. Step 2: Convert to fraction form
   1,208.42/1,811.46 = 386.10/x
3. Step 3: Cross multiply
   1,208.42x = 1,811.46 × 386.10
4. Step 4: Simplify right side
   1,208.42x = 699,406.15
5. Step 5: Solve for x
   x = 699,406.15/1,208.42
6. Step 6: Final answer
   x = 578.78