Finding the Fourth Proportional to 1,018.79, 1,406.79 and 646.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.79 : 1,406.79 = 646.43 : x
2. Step 2: Convert to fraction form
   1,018.79/1,406.79 = 646.43/x
3. Step 3: Cross multiply
   1,018.79x = 1,406.79 × 646.43
4. Step 4: Simplify right side
   1,018.79x = 909,391.26
5. Step 5: Solve for x
   x = 909,391.26/1,018.79
6. Step 6: Final answer
   x = 892.62