Finding the Fourth Proportional to 786.72, 1,086.56 and 681.63

Step by Step Solution

1. Step 1: Write the proportion equation
   786.72 : 1,086.56 = 681.63 : x
2. Step 2: Convert to fraction form
   786.72/1,086.56 = 681.63/x
3. Step 3: Cross multiply
   786.72x = 1,086.56 × 681.63
4. Step 4: Simplify right side
   786.72x = 740,631.89
5. Step 5: Solve for x
   x = 740,631.89/786.72
6. Step 6: Final answer
   x = 941.42