Finding the Fourth Proportional to 915.89, 1,257.83 and 768.27

Step by Step Solution

1. Step 1: Write the proportion equation
   915.89 : 1,257.83 = 768.27 : x
2. Step 2: Convert to fraction form
   915.89/1,257.83 = 768.27/x
3. Step 3: Cross multiply
   915.89x = 1,257.83 × 768.27
4. Step 4: Simplify right side
   915.89x = 966,354.97
5. Step 5: Solve for x
   x = 966,354.97/915.89
6. Step 6: Final answer
   x = 1,055.10