Finding the Fourth Proportional to 1,423.17, 2,131.75 and 727.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,423.17 : 2,131.75 = 727.72 : x
2. Step 2: Convert to fraction form
   1,423.17/2,131.75 = 727.72/x
3. Step 3: Cross multiply
   1,423.17x = 2,131.75 × 727.72
4. Step 4: Simplify right side
   1,423.17x = 1,551,312.69
5. Step 5: Solve for x
   x = 1,551,312.69/1,423.17
6. Step 6: Final answer
   x = 1,090.04