Finding the Fourth Proportional to 1,340.80, 2,009.04 and 826.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,340.80 : 2,009.04 = 826.72 : x
2. Step 2: Convert to fraction form
   1,340.80/2,009.04 = 826.72/x
3. Step 3: Cross multiply
   1,340.80x = 2,009.04 × 826.72
4. Step 4: Simplify right side
   1,340.80x = 1,660,913.55
5. Step 5: Solve for x
   x = 1,660,913.55/1,340.80
6. Step 6: Final answer
   x = 1,238.75