Finding the Fourth Proportional to 1,380.02, 1,904.36 and 820.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.02 : 1,904.36 = 820.54 : x
2. Step 2: Convert to fraction form
   1,380.02/1,904.36 = 820.54/x
3. Step 3: Cross multiply
   1,380.02x = 1,904.36 × 820.54
4. Step 4: Simplify right side
   1,380.02x = 1,562,603.55
5. Step 5: Solve for x
   x = 1,562,603.55/1,380.02
6. Step 6: Final answer
   x = 1,132.31