Finding the Fourth Proportional to 828.72, 1,142.52 and 688.32

Step by Step Solution

1. Step 1: Write the proportion equation
   828.72 : 1,142.52 = 688.32 : x
2. Step 2: Convert to fraction form
   828.72/1,142.52 = 688.32/x
3. Step 3: Cross multiply
   828.72x = 1,142.52 × 688.32
4. Step 4: Simplify right side
   828.72x = 786,419.37
5. Step 5: Solve for x
   x = 786,419.37/828.72
6. Step 6: Final answer
   x = 948.96