Finding the Fourth Proportional to 1,406.21, 1,940.10 and 909.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,406.21 : 1,940.10 = 909.48 : x
2. Step 2: Convert to fraction form
   1,406.21/1,940.10 = 909.48/x
3. Step 3: Cross multiply
   1,406.21x = 1,940.10 × 909.48
4. Step 4: Simplify right side
   1,406.21x = 1,764,482.15
5. Step 5: Solve for x
   x = 1,764,482.15/1,406.21
6. Step 6: Final answer
   x = 1,254.78