Finding the Fourth Proportional to 1,057.98, 1,584.33 and 641.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,057.98 : 1,584.33 = 641.29 : x
2. Step 2: Convert to fraction form
   1,057.98/1,584.33 = 641.29/x
3. Step 3: Cross multiply
   1,057.98x = 1,584.33 × 641.29
4. Step 4: Simplify right side
   1,057.98x = 1,016,014.99
5. Step 5: Solve for x
   x = 1,016,014.99/1,057.98
6. Step 6: Final answer
   x = 960.33