Finding the Fourth Proportional to 1,007.98, 1,391.17 and 588.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.98 : 1,391.17 = 588.40 : x
2. Step 2: Convert to fraction form
   1,007.98/1,391.17 = 588.40/x
3. Step 3: Cross multiply
   1,007.98x = 1,391.17 × 588.40
4. Step 4: Simplify right side
   1,007.98x = 818,564.43
5. Step 5: Solve for x
   x = 818,564.43/1,007.98
6. Step 6: Final answer
   x = 812.08