Finding the Fourth Proportional to 1,012.89, 1,397.81 and 564.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.89 : 1,397.81 = 564.80 : x
2. Step 2: Convert to fraction form
   1,012.89/1,397.81 = 564.80/x
3. Step 3: Cross multiply
   1,012.89x = 1,397.81 × 564.80
4. Step 4: Simplify right side
   1,012.89x = 789,473.27
5. Step 5: Solve for x
   x = 789,473.27/1,012.89
6. Step 6: Final answer
   x = 779.43