Finding the Fourth Proportional to 1,092.37, 1,638.84 and 399.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,092.37 : 1,638.84 = 399.10 : x
2. Step 2: Convert to fraction form
   1,092.37/1,638.84 = 399.10/x
3. Step 3: Cross multiply
   1,092.37x = 1,638.84 × 399.10
4. Step 4: Simplify right side
   1,092.37x = 654,061.04
5. Step 5: Solve for x
   x = 654,061.04/1,092.37
6. Step 6: Final answer
   x = 598.75