Finding the Fourth Proportional to 1,018.65, 1,405.33 and 664.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.65 : 1,405.33 = 664.45 : x
2. Step 2: Convert to fraction form
   1,018.65/1,405.33 = 664.45/x
3. Step 3: Cross multiply
   1,018.65x = 1,405.33 × 664.45
4. Step 4: Simplify right side
   1,018.65x = 933,771.94
5. Step 5: Solve for x
   x = 933,771.94/1,018.65
6. Step 6: Final answer
   x = 916.67