Finding the Fourth Proportional to 1,405.72, 1,939.98 and 1,172.44

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.72 : 1,939.98 = 1,172.44 : x
2. Step 2: Convert to fraction form
   1,405.72/1,939.98 = 1,172.44/x
3. Step 3: Cross multiply
   1,405.72x = 1,939.98 × 1,172.44
4. Step 4: Simplify right side
   1,405.72x = 2,274,510.15
5. Step 5: Solve for x
   x = 2,274,510.15/1,405.72
6. Step 6: Final answer
   x = 1,618.04