Finding the Fourth Proportional to 1,008.39, 1,391.61 and 566.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,008.39 : 1,391.61 = 566.40 : x
2. Step 2: Convert to fraction form
   1,008.39/1,391.61 = 566.40/x
3. Step 3: Cross multiply
   1,008.39x = 1,391.61 × 566.40
4. Step 4: Simplify right side
   1,008.39x = 788,200.95
5. Step 5: Solve for x
   x = 788,200.95/1,008.39
6. Step 6: Final answer
   x = 781.65