Finding the Fourth Proportional to 1,380.82, 2,071.50 and 406.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.82 : 2,071.50 = 406.98 : x
2. Step 2: Convert to fraction form
   1,380.82/2,071.50 = 406.98/x
3. Step 3: Cross multiply
   1,380.82x = 2,071.50 × 406.98
4. Step 4: Simplify right side
   1,380.82x = 843,059.07
5. Step 5: Solve for x
   x = 843,059.07/1,380.82
6. Step 6: Final answer
   x = 610.55