Finding the Fourth Proportional to 1,380.08, 1,904.42 and 820.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.08 : 1,904.42 = 820.52 : x
2. Step 2: Convert to fraction form
   1,380.08/1,904.42 = 820.52/x
3. Step 3: Cross multiply
   1,380.08x = 1,904.42 × 820.52
4. Step 4: Simplify right side
   1,380.08x = 1,562,614.70
5. Step 5: Solve for x
   x = 1,562,614.70/1,380.08
6. Step 6: Final answer
   x = 1,132.26