Finding the Third Proportional to 670.78 and 994.78

Step by Step Solution

1. Step 1: Write the proportion equation
   670.78 : 994.78 = 994.78 : x
2. Step 2: Convert to fraction form
   670.78/994.78 = 994.78/x
3. Step 3: Cross multiply
   670.78x = 994.78 × 994.78
4. Step 4: Simplify right side
   670.78x = 989,589.74
5. Step 5: Solve for x
   x = 989,589.74/670.78
6. Step 6: Final answer
   x = 1,475.28