Finding the Fourth Proportional to 1,018.72, 1,406.46 and 646.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.72 : 1,406.46 = 646.24 : x
2. Step 2: Convert to fraction form
   1,018.72/1,406.46 = 646.24/x
3. Step 3: Cross multiply
   1,018.72x = 1,406.46 × 646.24
4. Step 4: Simplify right side
   1,018.72x = 908,910.71
5. Step 5: Solve for x
   x = 908,910.71/1,018.72
6. Step 6: Final answer
   x = 892.21