Finding the Fourth Proportional to 789.16, 1,086.56 and 670.88

Step by Step Solution

1. Step 1: Write the proportion equation
   789.16 : 1,086.56 = 670.88 : x
2. Step 2: Convert to fraction form
   789.16/1,086.56 = 670.88/x
3. Step 3: Cross multiply
   789.16x = 1,086.56 × 670.88
4. Step 4: Simplify right side
   789.16x = 728,951.37
5. Step 5: Solve for x
   x = 728,951.37/789.16
6. Step 6: Final answer
   x = 923.71