Finding the Fourth Proportional to 1,007.89, 1,390.81 and 588.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.89 : 1,390.81 = 588.26 : x
2. Step 2: Convert to fraction form
   1,007.89/1,390.81 = 588.26/x
3. Step 3: Cross multiply
   1,007.89x = 1,390.81 × 588.26
4. Step 4: Simplify right side
   1,007.89x = 818,157.89
5. Step 5: Solve for x
   x = 818,157.89/1,007.89
6. Step 6: Final answer
   x = 811.75