Finding the Fourth Proportional to 1,057.80, 1,459.59 and 664.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.80 : 1,459.59 = 664.54 : x
2. Step 2: Convert to fraction form
   1,057.80/1,459.59 = 664.54/x
3. Step 3: Cross multiply
   1,057.80x = 1,459.59 × 664.54
4. Step 4: Simplify right side
   1,057.80x = 969,955.27
5. Step 5: Solve for x
   x = 969,955.27/1,057.80
6. Step 6: Final answer
   x = 916.96