Finding the Fourth Proportional to 1,083.30, 1,622.55 and 939.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,083.30 : 1,622.55 = 939.30 : x
2. Step 2: Convert to fraction form
   1,083.30/1,622.55 = 939.30/x
3. Step 3: Cross multiply
   1,083.30x = 1,622.55 × 939.30
4. Step 4: Simplify right side
   1,083.30x = 1,524,061.22
5. Step 5: Solve for x
   x = 1,524,061.22/1,083.30
6. Step 6: Final answer
   x = 1,406.87