Finding the Fourth Proportional to 1,388.48, 2,082.69 and 414.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.48 : 2,082.69 = 414.59 : x
2. Step 2: Convert to fraction form
   1,388.48/2,082.69 = 414.59/x
3. Step 3: Cross multiply
   1,388.48x = 2,082.69 × 414.59
4. Step 4: Simplify right side
   1,388.48x = 863,452.03
5. Step 5: Solve for x
   x = 863,452.03/1,388.48
6. Step 6: Final answer
   x = 621.87