Finding the Third Proportional to 771.40 and 1,156.78

Step by Step Solution

1. Step 1: Write the proportion equation
   771.40 : 1,156.78 = 1,156.78 : x
2. Step 2: Convert to fraction form
   771.40/1,156.78 = 1,156.78/x
3. Step 3: Cross multiply
   771.40x = 1,156.78 × 1,156.78
4. Step 4: Simplify right side
   771.40x = 1,338,142.86
5. Step 5: Solve for x
   x = 1,338,142.86/771.40
6. Step 6: Final answer
   x = 1,734.70