Finding the Fourth Proportional to 789.98, 1,086.78 and 715.46

Step by Step Solution

1. Step 1: Write the proportion equation
   789.98 : 1,086.78 = 715.46 : x
2. Step 2: Convert to fraction form
   789.98/1,086.78 = 715.46/x
3. Step 3: Cross multiply
   789.98x = 1,086.78 × 715.46
4. Step 4: Simplify right side
   789.98x = 777,547.62
5. Step 5: Solve for x
   x = 777,547.62/789.98
6. Step 6: Final answer
   x = 984.26