Finding the Fourth Proportional to 1,443.78, 2,165.71 and 456.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.78 : 2,165.71 = 456.60 : x
2. Step 2: Convert to fraction form
   1,443.78/2,165.71 = 456.60/x
3. Step 3: Cross multiply
   1,443.78x = 2,165.71 × 456.60
4. Step 4: Simplify right side
   1,443.78x = 988,863.19
5. Step 5: Solve for x
   x = 988,863.19/1,443.78
6. Step 6: Final answer
   x = 684.91