Finding the Fourth Proportional to 1,380.71, 2,071.50 and 406.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.71 : 2,071.50 = 406.82 : x
2. Step 2: Convert to fraction form
   1,380.71/2,071.50 = 406.82/x
3. Step 3: Cross multiply
   1,380.71x = 2,071.50 × 406.82
4. Step 4: Simplify right side
   1,380.71x = 842,717.27
5. Step 5: Solve for x
   x = 842,717.27/1,380.71
6. Step 6: Final answer
   x = 610.35