Finding the Fourth Proportional to 1,405.72, 1,939.53 and 909.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.72 : 1,939.53 = 909.01 : x
2. Step 2: Convert to fraction form
   1,405.72/1,939.53 = 909.01/x
3. Step 3: Cross multiply
   1,405.72x = 1,939.53 × 909.01
4. Step 4: Simplify right side
   1,405.72x = 1,763,052.17
5. Step 5: Solve for x
   x = 1,763,052.17/1,405.72
6. Step 6: Final answer
   x = 1,254.20