Finding the Fourth Proportional to 1,405.90, 1,940.88 and 909.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.90 : 1,940.88 = 909.22 : x
2. Step 2: Convert to fraction form
   1,405.90/1,940.88 = 909.22/x
3. Step 3: Cross multiply
   1,405.90x = 1,940.88 × 909.22
4. Step 4: Simplify right side
   1,405.90x = 1,764,686.91
5. Step 5: Solve for x
   x = 1,764,686.91/1,405.90
6. Step 6: Final answer
   x = 1,255.20