Finding the Fourth Proportional to 1,008.57, 1,391.67 and 566.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.57 : 1,391.67 = 566.40 : x
2. Step 2: Convert to fraction form
   1,008.57/1,391.67 = 566.40/x
3. Step 3: Cross multiply
   1,008.57x = 1,391.67 × 566.40
4. Step 4: Simplify right side
   1,008.57x = 788,241.89
5. Step 5: Solve for x
   x = 788,241.89/1,008.57
6. Step 6: Final answer
   x = 781.54